SMS_S2016_03

Structural Materials Selection Spring 2016 Session · 8 sections 16 cases · Watch on YouTube ↗ all files
Layer 3 — readable edition

§1. Class management: presentations and procrastination [00:00]

§1.p1

I'm in favor of not procrastinating — get it done early. My father taught me when I was five years old: if you're old enough to be an adult, you should act like an adult. And he held me to that standard. My older brother didn't do so well to it; he had fights with my father, but I found it was just easier to get it done.

§1.p2

The way I learned not to procrastinate — he'd ask my older brother, have you finished such-and-such? My brother would say no, and he'd get upset with him. When I was about seven or eight, he came to me and did the same thing. I said, yep, all done. He would never congratulate me, but I could tell he was pleased. I reacted positively; my brother reacted negatively to the same inputs.

§1.p3

I know people who say, I do my best work when I'm under pressure. I think that's absolute fallacy. I don't think anyone does their best work when they don't have time to do a good job. I think that's an oxymoron, but anyway, that's another story.

§1.p4

Let's talk about the presentations. The presentation should be limited in scope. I don't want you to come in and spend ten minutes telling us how to solve world hunger. You can get those types of stories out of the Wall Street Journal, and they're worthless, they're not worth reading.

§1.p5

I did give a couple of B's last year because people came in and gave me stories like that. One of them just paraphrased what they'd read in the New York Times about ultra-lightweight composites in Boeing aircraft. At the end of the story they sort of admitted they would never use these composites because they were too expensive and they had no structural integrity — they were so lightweight that they just collapsed. Things like aerogels. An aerogel has a density half that of water, and if you blow on it, it will collapse. It has about the structural integrity of a soap bubble. Put any stress on it and it collapses.

§1.p6

They came in and told us this wonderful story about how aerogels were going to take over the world. This was an article from fifteen years ago. I said, so are they using them? Well, no, not yet. What do you mean, no, not yet? You just told us this was the wonder material of the future. I didn't say that to him in class, but I did give them a B.

§1.p7

So I want something of substance — you're at MIT. And I don't want it to be too general. Using my own talk yesterday as an example: I didn't do 3D printing in general or additive manufacturing in general, I did 3D printing of metals. I could have given you that presentation in ten PowerPoints — Prandtl number, Bond number, and whichever other dimensionless number, on one overhead — and said these are the properties of metals, and talked about the limitations of doing 3D printing of metals. That's something of substance that hopefully most of you didn't already know, so you learn something from it. That's what I want from you. I took fifty minutes, but I'm the professor, I have a certain literary license.

§1.p8

When you're doing a presentation, you don't have to explain everything. That's what questions and answers are for. You're just trying to introduce the topic. So don't tell me about use of composites in automobiles — that's a little broad. If you want to say use of aluminum-silicon-carbide calipers for lightweight disc brakes, great, that's specific enough, and you can get down to why they do it or why they don't do it.

§1.p9

That's actually an example from twenty-five years ago. People were all excited about using aluminum-silicon-carbide composites for brake calipers, and they found everything was fine until you hit the brakes very hard. The aluminum heated up and crept, and all of a sudden your calipers no longer had the same shape, and they wouldn't squeeze the brakes anymore. Minor problem: brake fade. Hit your brakes hard three times in a row and you have no brakes, and you never will have brakes — you have to replace them because they just deformed out of shape.

§2. Yesterday's sound bites: limits to material properties [05:36]

§2.p1

If I remember and have time each day, I'll try to give you my sound bites from the day before. I wouldn't have expected any of you to be able to generalize what I talked about in 3D printing into these themes. But one of them is: material selection is a multi-dimensional problem. People say, why don't we just do 3D printing of metals? Well, there are quite a few reasons, and I spent a whole hour going through them. It's a more complex problem than just substituting plastic for metal in your 3D print head. It involves mechanical and melting problems, and I organized it that way. Most things we'll talk about in material selection are multi-dimensional. You can use a material, dig it out of the ground — sometimes the biggest problem is recycling it. People don't always think about that.

§2.p2

We also talked about Ashby plots, and Ashby plots basically tell us there are limits to material properties. We'd love to have a material with a strength of 5 million psi. Why can't we do that? The strongest material we can get is about 3 million psi, and that has to do with the strength of the individual chemical bonds. What's the strongest bond in the world? Most people say carbon, because that's what we have in diamond, which is the strongest material. It's not the strongest bond. If you're a chemist, it's a silicon-oxygen-silicon bond. I told you that yesterday — silicone rubber has the highest melting temperature of any of the rubbers, 500 degrees, and it's because that backbone of silicon-oxygen-silicon, as opposed to the Kevlar backbone of carbon-carbon, is actually stronger.

§2.p3

If you calculate what the strength of that bond is going to be, you get about 3 million psi. You know about this because you've read in the New York Times and the Wall Street Journal all about carbon nanotubes, and they have a strength of 3 million psi. Well, that's a calculation that was done in the 1930s when we first learned quantum mechanics and learned something about bond energy. If you take my solid-state welding course, I spend half a lecture on this. We're limited in our material properties by the strength of the chemical bonds between the atoms. There's a fundamental limitation. You can't get a material with a modulus higher than 60 million psi — about 400 gigapascals if you're metric. Unless you come up with new elements that have stronger bonds, we're not going to get anything stronger.

§2.p4

What's the problem with the 3 million psi of carbon nanotubes? It's the fact that we have defects. I've told you about fracture mechanics and Griffith — little notches can weaken the strength of things. There's the Bob Spray quote that material scientists know it's defects that control properties. A perfect carbon nanotube would have a strength of 3 million psi, but does anyone know of anyone who's ever measured that? How do you grip a little carbon nanotube to measure tensile strength? And if you did, you'd find it probably has about one tenth of that strength. There will be vacancies in there. In that perfect little carbon nanotube there's going to be a missing carbon atom. At any temperature above absolute zero, thermodynamics — the entropy — tells us we're going to have a vacancy. That's a defect, and it will create a stress concentration and be much weaker, maybe ten times weaker. So all of you working on carbon nanotubes for structural applications, you'll get a thesis out of it; you just won't get a useful product. We've known these things for sixty years.

§2.p5

Some physicist down at Rice University, who thought he should win the Nobel Prize — actually I think he did, for discovering buckyballs — did the calculation that had been done in the 1930s and took credit for it. "I've discovered a new material that's going to be ten times stronger than anything else we have." In the 1940s we actually measured iron whiskers with a strength of 2.2 million psi, and we got around the defects of the dislocations because the iron whisker was a single crystal with a screw dislocation right down the axis. When you pulled on it there was no stress on the dislocation — if you know about dislocations and Burgers vectors — and you got 2.2 million psi. A student about twenty years ago asked, how do you do that calculation? I'd explained how you would do it, and they challenged me. I went back to my office, in five minutes I'd scratched it out, got 2.2 million psi for the strength of iron. It's just the strength of the chemical bond between two iron atoms. The calculation was done ninety years ago. But this guy twenty years ago discovers buckyballs and wins the Nobel Prize because he goes around the press: I've discovered a new material that's going to revolutionize the world. He discovered those twenty, twenty-five years ago. Have buckyballs revolutionized your world? Don't think so. Although it has, for all of you doing research — there's a lot of research money to study this.

§2.p6

So there are limits to material properties, and we'll talk about those limits in more detail. That's the summary — I've gone through twenty-five percent of this lecture just summarizing the last one, but hopefully pointing out some other things.

§3. Why we don't 3D-print metals — and how, actually, we have for eighty years [12:27]

§3.p1

I did want to finish up this stuff on why we don't do 3D printing of metals. [Tom passes around a laser-printed metal part from Dr. Belmar.] This is a five-hundred-dollar part, laser printed. I'm sure it took hours — he didn't know how long, but just knowing the solidification process of thin layers, that part took hours to produce. That's why it costs five hundred dollars. So you can 3D print metals, not very economically, but you can do it. If you're talking about something that's going to go in outer space, that's great.

§3.p2

I told you we were trying to make propellers for the Navy so they wouldn't have to buy castings and let them sit in a warehouse for a year in case the propeller broke. We tried some stainless steel because it was easy — simple geometries. You can see on the edge we started to get some imperfect melting, and that defect propagated and got larger because of surface tension. The first part gets a little wavy, but it didn't look too bad. All of that is due to the surface tension of metals, which is ten times higher than the surface tension of other materials.

§3.p3

This one I think I may have passed around. It's actually a pretty good deposit. You'll see some little humps on either end because you scan this way and then back that way, and there's a delay as you go from a finite velocity in one direction and have to accelerate in the other. So you build up a little more material on each end, and that's just Isaac Newton — you can't make an infinite change in speed.

§3.p4

It's just a wire of manganese-aluminum-bronze welding wire — actually a tube, manganese-aluminum-bronze tube — and we just went around in circles. We did it with an electron beam, for reasons of the Bond number and the high heat transfer coefficient you need to solidify metals. Manganese-aluminum-bronze has a better wetting and surface-tension balance than some other things. You can see we were reasonably successful with that, although we're still going to end up with tremendous residual stresses. It's a fairly simple process.

§3.p5

So the question posed to me by the Technology Review editor was, why don't we do 3D printing of metals? At the end of spending an hour with them, I said, but in fact we do, and we have been for eighty years. For example, the US Air Force about twenty-five years ago decided they needed to rebuild the tips of turbine vanes. These vanes go into a jet engine, they're spinning around, they get hot, they creep and get a little longer, and they wear out the top edge. They wanted to rebuild them — the thing's still good for another three thousand hours of use. They built a little arc welding machine, called it the dabber, and they would build up the edge and machine it back. You're talking about a vane that might be worth five hundred dollars — you can afford to spend a couple hundred dollars to repair it if you're getting a brand new vane. High-value-added part, high heat intensity, very limited geometry. They grew the thin vane an extra quarter of an inch, and then reamed it; it's not critical, it's not a lot of stress on it in service. The big stresses are down at the base where you have the biggest centrifugal forces. The tip doesn't.

§3.p6

The Air Force automated it in their Oklahoma City repair facility — it's a ten-million-dollar machine because of all that precise alignment and control. But they were going to make fifty million dollars with the blades on a ten-million-dollar machine.

§3.p7

So we have not solved the problem of 3D printing of printed circuit boards, but we have done things for eighty years. There's a billion-dollar industry called thermal spraying where we repair old worn-out parts. Companies like Eutectic Castolin — a four or five hundred million dollar a year company — make all kinds of metal powders, put them in a flame, and you take a piece of metal and flame-spray, or thermal-spray, this powder on top of the metal. You might melt it, in which case you probably have to preheat to a very high temperature, because of some of the things we talked about. They've been doing thermal spray repair of parts for eighty or ninety years. Usually nice circular parts or flat parts, not complex geometries, but we have been building things up by additive manufacturing for years and years.

§3.p8

I visited POSCO Steel when it was the largest steel plant in the world, in Pohang, Korea. They took me through a facility where they refurbished the rolls for the continuous caster. These rolls are about twelve feet long, a foot in diameter. A molten band of hot steel comes down out of the casting machine — about seven or eight stories tall — and gets bent ninety degrees, and these rolls, hundreds of them, are bending this hot steel. They wear out — they're touching steel at above a thousand degrees centigrade. They're water-cooled in service, but the surface is touching something basically 1200 degrees centigrade, so they get thermal cracking. So they take them into the shop — about half the size of a football field, lots of lathes. They'd have this twelve-foot roll, do a pass and cut off the bad stuff on the surface. Then they'd preheat the whole thing. There were flames all over the shop — I think I was there in August, it was pretty hot — great big flames preheating to six, seven, eight hundred degrees Fahrenheit. Then just laying down weld metal. They got around the residual stresses because with the flame temperatures they're stress-relieving as they go. They're building up massive metal on the outside of these rolls. They have to replace them periodically, probably after two weeks of service, and this machine runs continuously for two or three years. So we do lots of buildup of metal parts.

§3.p9

Another example: fancier turbine blades — the ones in the hot section of the engine. I've seen two places where they're doing electron beam, adding the tip or melting in there, and they're preheating to a thousand degrees centigrade, 1800 degrees Fahrenheit, because of this problem of sucking out the heat and the fact that the nickel-based superalloys are very prone to cracking. If you have big thermal stresses, you'll get cracks. So they preheat to within a couple hundred degrees of the melting point. We do it, it's just tricky and expensive, and you don't do this on twenty-seven-pound parts — you do it on very high-value-added parts.

§3.p10

So 3D printing is a wonderful technology. Nanotechnology is a technology — I won't use the word wonderful with it — that is oversold.

§4. Productivity vs. competitiveness [21:25]

§4.p1

Let's start, after two and a half hours, actually talking about what we're going to do in this course. Lecture 1, which starts today, is on externalities. Then we'll go to price, costs, and abundance, and talk about limits of properties, which we've already talked about. We'll talk about materials manufacturing productivity — spend a fair amount of time on the productivity of different materials: steel, aluminum, composites. You're going to hear the word steel a lot in this course. Usually after two or three days of lectures the students start making jokes about all he ever talks about is steel. You'll find out why in a little bit. There are statistics on steel that will probably surprise you.

§4.p2

Student: [What's the difference between productivity and competitiveness?]

§4.p3

Exactly. It's relative, and it involves things like the price of labor in one country versus another. Productivity is how well you can make something, and it's sort of independent of things like labor rates, yen-dollar exchange, yuan-dollar exchange — those exchange rates are part of competitiveness. Can the Japanese make something cheaper than the Americans? Can the Indians make something cheaper than the Americans, at equal quality? Competitiveness is a huge, all-encompassing issue. Productivity is how efficiently you can manufacture something, usually measured in person-hours per ton or person-hours per gram — some amount of effort per quantity.

§4.p4

Back in the mid-1980s — before you were born — the Japanese were eating our lunch. Something like seventy-five percent of Japan's workforce was involved in something that had to do with exporting. The Japanese were selling Toyotas here that were better quality than any of the GM junk being produced. Then GM's improved significantly, and there are a number of books that were written about this. One of them was Dan Roos's book — he was the second author — Lean Manufacturing. You've all heard of lean manufacturing, a term coined by a professor in civil engineering here who was an expert in the automotive industry. Dan Roos twenty years ago was personal friends with the CEO of every major automotive company in the world. He did a study of why Toyota was eating our lunch, and he pointed out they were using lean manufacturing production technologies, which is now a very big buzzword, but in the mid-1980s it wasn't.

§4.p5

In the meantime, mid-1980s, I was a young professor — probably wasn't even a full professor at the time — and a guy named Jerry Wilson was the Dean of Engineering, and he was very concerned about the declining productivity of the American industrial sector. People were looking at manufacturing employment in the United States and it was just decreasing. Back in 1980, over twenty percent of the workforce in the United States was employed in manufacturing — high-value jobs, United Auto Workers. These people made enough money to buy a home and a car and send their kids to college. And the workforce was decreasing.

§4.p6

There was a guy at General Motors, the vice president, very big on robotics. He was going to eliminate all the hourly workers at General Motors. GM always despised the hourly workers, and it was mutual distrust between the two — terrible labor fights. These are some of the externalities that go on. This is before we had PowerPoint, and I used to see some of his presentations — he'd have $50,000 audiovisual presentations on what General Motors was doing with laser manufacturing. During the decade of the 1980s, General Motors spent fifty billion dollars automating their manufacturing facilities. Did you know that in the 1980s, if it had been legal in Japan to purchase Toyota on the stock market for a foreign company, General Motors could have purchased Toyota for fifty billion dollars? They couldn't, because Japanese laws — that's another externality — wouldn't allow an American company to purchase stock of a Japanese company in Japan.

§5. The MIT Commission on Industrial Productivity and the yen-dollar story [27:16]

§5.p1

The Japanese were eating our lunch, and so Jerry Wilson commissioned a book written by Michael Dertouzos, who was head of CSAIL, the computer science lab — almost became president of MIT. Michael's passed away now. He was a Greek, a consultant to the premier of Greece. I remember at Engineering Council they were complaining once that the assistant professors didn't make enough money to live on in the Boston area, and Michael said, well let them go out and consult, I can make twenty thousand dollars a day. I said, what? That's the kind of money Michael was making consulting for the government of Greece. Richard Lester is still around; Bob Solow won the Nobel Prize in economics. These guys were asked to be part of the MIT Commission on Industrial Productivity in the mid-'80s, and they wrote this book. I was a commission member and did something on productivity in the steel industry.

§5.p2

This is the opening part of the book, and I've highlighted the first sentence: to live well a nation must produce well. That's what the whole book was about — why was the United States not as productive as Japan in manufacturing. I'd spent my sabbatical in 1984 and '85 in Japan. I'd walked around these factories and research labs, and they certainly didn't seem like they were as productive as the American factories I'd been through. And it turns out they weren't. They were more competitive because at the time the yen-dollar exchange — when I was renting my home in Tokyo, the exchange rate was 240 yen to the dollar. What is it today? About a hundred yen to the dollar.

§5.p3

So what had happened in the 1980s: Toyota wanted to sell in the United States because we were the world's market — one third of the world's gross domestic product. Everyone wanted to sell in the United States. Toyota was manufacturing cars in Japan, doing a wonderful job with lean production, and shipping to the United States. Ronald Reagan in the meantime was doing Star Wars, he was going to defeat the Soviet Union. And he did — he defeated them economically by bankrupting them. They couldn't keep up with all the money we were spending on Star Wars. The Soviet Union fell apart in the early 1990s for economic reasons.

§5.p4

The Japanese were loaning us money — we were running huge federal deficits we'd never run before, because Reagan was going to outspend the Soviets. The Japanese were loaning us money at 240 yen to the dollar so we could purchase their Toyotas. And we did. They were better cars than General Motors, and there was a big upheaval. Eventually we had to pay the piper, and we're now paying the Japanese back at a hundred yen to the dollar. So we're taking our sixty percent discount, because the Japanese thought they could just suck up those dollars and keep hoarding them — except it doesn't work that way.

§5.p5

There's another country doing that right now. What's that country? Who's doing all the manufacturing in the world, where everything you get says Made in China? You've heard about fights over the yuan-dollar exchange rate? The Chinese have trillions of dollars. And now they're finding, you can't eat dollars. You might be able to buy something with dollars, but they don't taste good. Eventually they're going to have to let the yuan float in the international currency, and we will be paying the Chinese back. All these VCRs and things we've been buying from them, we're going to pay them back twenty cents on the dollar. They're not going to be happy about getting twenty cents on the dollar for the trillions of dollars worth of goods they manufactured and sold us.

§5.p6

There's only one country in the world that can do this — the country whose currency is the market for energy. The price of oil is denominated in dollars around the whole world. Whoever controls the dollar is defining the world's currency, and everyone else has to adjust to where we're the reference point. You're seeing this right now. The European currencies are being devalued with regard to the dollar. Why? It turns out, to live well a nation must produce well. Which country has had the highest manufacturing productivity rate for the last hundred years? The United States. We are the most efficient producers — even in the 1980s when we were buying Toyotas to build Star Wars and to drive the Toyotas, and the Japanese were loaning us the money to do it, we still had better productivity.

§6. Comparative advantage and the productivity-employment paradox [33:33]

§6.p1

And why were we building Star Wars and the Japanese were building cars and someone else in Taiwan was building whisk brooms? It's called the law of comparative advantage. If we can both make a computer, but I can make it faster and more productively, less cost, than you — and I can also make the computer chip better than you, comparatively five times better — I'll make the computer chip, I'll let you assemble the computers. I could do both, but I'd rather take the comparative advantage of making the high-value part. Or I'd like to be Boeing — get the high value of assembling and designing the aircraft, and let you build some components I'll stick on in my factory. The law of comparative advantage: I'm going to take the high-value stuff, I'm going to leave you the lower-value stuff.

§6.p2

We have the highest productivity in the world, and we always have for the last hundred years. We stole it from the British, who had it in the industrial revolution. Why has manufacturing employment been going down for the last fifty years in the United States? Because our productivity has been going up. Everybody thinks, if you read the Wall Street Journal, we're losing our manufacturing competitiveness — all the jobs are going offshore. The jobs we don't want are going offshore. We're exporting our pollution. Let the Chinese make the stuff that pollutes. We want nice pretty views, we want to walk through clean air; we'll let them choke on their smog. This is what we do because we have been the world's dominant productivity king for a century. And the world buys its energy, and energy determines cost of things in general in dollars. Whoever has the gold rules — the golden rule. We have the dollar, as long as we keep our productivity up.

§6.p3

I actually used to give a talk on this. At the time of the American Revolution and Constitution and George Washington — anyone have any idea what fraction of the workforce was involved in agriculture in 1790? Seven percent? Ninety-seven percent. Ninety-seven out of a hundred were toiling away to make food, and they made enough extra that three percent of the people could be George Washington or Thomas Jefferson or Ben Franklin. Those people were in the minority. If I went back to 1980, what fraction of the United States population was working in food production? Three percent. We had a thirty-fold improvement in two hundred years in productivity in food production, which is a pretty basic need.

§6.p4

What fraction is it today? About one and a half percent. We're losing those farm jobs — haven't you read that in the Wall Street Journal? Rural America, they're all moving to the cities. Why? Because the law of comparative advantage. You might have been able to live for free on the family farm, but you can come here and pay twenty-five hundred dollars a month for a two-room apartment. That's competitiveness. To live well a nation must produce well is the beginning of Made in America. And it's Paul Krugman — who's Paul Krugman? He's an economist, started at MIT, went to Stanford, won the Nobel Prize, now he's at Princeton. Another one of these people Lester Thurow was talking about — they tend to hire our extinct volcanoes. As Paul Krugman says, productivity isn't everything, but in the long run it's nearly everything.

§7. Political externalities: rare earths and oil [38:27]

§7.p1

So what are the things that determine productivity in materials selection and economics? Well, there are externalities. Anyone taking an economics course know what an externality is? Right out of Wikipedia, which is the source of all knowledge: in economics, an externality is the cost or benefit that affects a party who did not choose to incur that cost or benefit. Something external, like air pollution. All the rest of us have to endure air pollution because someone designed and built these trucks that are dirty.

§7.p2

There are lots of different types of externalities. Political — there are political externalities. Rare earth metals. What's the political externality of the last eight years on rare earth metals, and why are rare earth metals important? We export our pollution — let someone else breathe that air. You've heard of neodymium-iron-boron magnets? Neodymium is a rare earth metal. Samarium-cobalt magnets. Rare earth metals are functional materials, not really structural materials, but functional materials used in many high-value applications.

§7.p3

About eight years ago — you were maybe in elementary school — it turns out China has tremendous rare earth metal reserves. They're not really that rare; it's a misnomer. The United States has tremendous reserves too, but China has lots of rare earth ores. It is a very dirty process — you think you're in the Black Hole of Calcutta to go see a rare earth metal plant. People die at an early age who do this, because they do it by technology that's a hundred years old. The Chinese had dropped the price — the law of comparative advantage. We had produced rare earth metals back in the 1970s and 1980s, but as China opened up after Richard Nixon, the Chinese decided they had all these reserves, they had cheap labor, they weren't worried about pollution, and they could produce rare earth metals cheaper than anybody else. So all the American mines and factories shut down — it's a dirty industry, they were going to get fined by the EPA anyway, so send it to China.

§7.p4

And the Chinese, all of a sudden, were producing ninety percent of the world's rare earth, and they decided they were having a fight with Japan. Who needs all these rare earth metals in their magnets and batteries? The Japanese, for their consumer electronics. It's replaced automobiles as one of the big high-value export industries in Japan. The Chinese just decided, we're going to put an embargo on, we're not going to ship you any rare earth metals. The Japanese government and the companies went berserk. They were going to be shut down because they couldn't get this critical material. It wasn't rare, but the Chinese had a de facto monopoly because everyone else had gotten out of the business. So for the last six or seven years, half the faculty at MIT working on materials are dabbling in some way to produce rare earth metals by a clean technology, so the next time the Chinese pull this stunt, we'll be ready.

§7.p5

Same thing happened in 1973 with the Arab oil embargo. We were all buying two-dollar-a-barrel gasoline — crude oil was being pumped out of Saudi Arabia for two dollars a barrel in 1972, and all of a sudden the Arabs got together and said we're not going to ship you any more crude oil. The world economy came to a screeching halt in many areas. The price of energy shot up — we called it the oil crisis. My wife and I, and everybody else, would sit in line for four or five hours waiting to fill up our gas tank. All these cars running their engines sitting in lines a hundred yards long. Wonderful.

§7.p6

They tried it again in 1978, and by 1978 it was nowhere near as effective, because all the American industry said we're not going to let you do that to us again. We can use natural gas or oil, and we can flick a switch. American industry spent millions of dollars to be able to switch from firing electrical plants with oil or gas. So the next time they had an oil embargo, we'd just switch. Yes, the price of gas went up, but nowhere near as big a disruption as in 1973. The try in 1982 wasn't so effective.

§7.p7

Now forty years later, Saudi Arabia decided they didn't like all the other oil cartel folks cheating on them. Saudi Arabia can pump twelve million barrels a day at a production cost of five dollars a barrel, and they were selling at a hundred dollars a barrel. They were very wealthy. Now they decided, we're not going to keep losing market share. They were at nine or ten million barrels a day, and every time there was a little price increase, the Saudis would lose market share because Nigeria would just keep pumping. Nigeria is one of the most corrupt countries in the world, and they'd violate all the cartel quotas — their production cost is about ninety dollars a barrel. Finally Saudi Arabia said, we're going to shut down those frackers in the United States and we're going to put Nigeria out of business, because they've been cheating on us for thirty years. We can keep pumping oil all the way down to five dollars a barrel and make money. Nigeria's hemorrhaging at ninety dollars a barrel with a price of thirty. How'd you like to be in Nigeria right now? All those sins of the past are coming back.

§7.p8

Our frackers' marginal production cost, once you've already drilled the well, is slightly less than thirty dollars a barrel. They can barely make it right now, but they can. They can't drill a lot of new wells, but the Saudis have not driven them out of business yet. They will eventually drive some of them out of business. So there are political externalities. They have nothing to do with the technology of buying a particular type of oil or product.

§8. Economic and social externalities: Oil City, lead, mercury [47:06]

§8.p1

Economic externalities. I had an explosion — someone was welding on an oil storage tank in Oil City, Pennsylvania. Oil City is just down the river from Titusville. Do you know what Titusville, Pennsylvania is famous for? Edwin Drake discovered oil in 1857 — he drilled for oil. Before that, the only oil one had was bubbling up out of the ground on the North Slope of Alaska or the oil sands in Alberta, where oil is right on the surface. But Edwin Drake actually drilled for it, found it, rather than drilling for water. They built a refinery there around the 1890s in Oil City, Pennsylvania.

§8.p2

They had an explosion and killed someone, and I had to go out there. This was around 1995. I get to Oil City — it's not the easiest place to get to. The first time, it didn't make any sense: old riveted 1920s storage tanks; the tank farm had two or three feet of gravel; if you dug down about a foot you'd strike oil because for the last hundred years they'd been spilling oil from the tank farm, so the ground was saturated. It's a small production facility. To me, a thirty-thousand-gallon storage tank — you go down to Houston, some refinery, there's a hundred-thousand-gallon storage tank. Why was Pennzoil keeping this plant running? It makes no sense economically.

§8.p3

Well, it made perfect sense economically. I figured it out the next morning at breakfast. They couldn't afford to shut it. Because as long as they were operating, the EPA had no control over them other than to keep them from polluting off their premises. But the law is such that if you're an operating facility, the government is not going to touch those jobs. When you shut the plant, the EPA comes in, and you're no longer protecting jobs — they will assess you billions of dollars in cleanup costs. So Pennzoil was keeping this inefficient refinery operating in 1995 because they couldn't afford to shut it. It was a money loser. But if they shut it and put all these people out of work, it would be a humongous money loser because the EPA would make them clean it up.

§8.p4

Since then they have shut it — it's too inefficient — and they do have to clean it up, and they're cleaning it up; the rules have changed over the years. Do you know how they used to get the oil from Titusville, just up the river, down to Oil City? Just floated it on the river and skimmed it off at the other end. Nowadays you see an oil sheen on the water and the environmentalists are out there to put you in jail as a felon. Back in those days there were no fish in that river — they all had oil for dinner. So Oil City, Pennsylvania, and Pennzoil. Sometimes the regulations won't let you choose the best material.

§8.p5

Social externalities. Lead. What do we know about lead? Flint, Michigan is in the news. My wife and I rented a house down the street ten houses down — moved in October, we'd lived in our other house for thirty-seven years. Last week they came in to start the construction. You can go through my house, see the studs, see the outside walls. I'm ripping out all the plumbing, all the wiring, in this ninety-year-old house. I wanted to get rid of the lead paint. One of these days that old house, built in the 1930s, they're going to come by and I'll never be able to sell it — it's got lead paint. Some environmentalist is going to say you can't sell a house that has lead paint. The rules were different in 1938. But there's no lead paint in that house anymore — it's all in the dumpster.

§8.p6

Mercury. Where's mercury used? Used to be in lots of things, but there's mercury all over this room — look at the fluorescent lights, every one has an arc igniter that uses a little mercury. Why can't you dispose of a fluorescent light in the regular old dumpster? Because it's got mercury in it. For environmental reasons we try to get rid of mercury. Diamonds — there are social reasons there. Blood diamonds, they're making movies about this stuff now. There are all kinds of things. We're running out of time. I'll talk about some of the other externalities tomorrow, but there are all kinds of social.

Cases referenced

  • Aerogel as structural material (New York Times article case) §1.p5

    Example of a student presentation that paraphrased press coverage of a "wonder material" without checking whether it had ever been deployed. Used as a cautionary tale about presentation scope.

  • Aluminum silicon carbide brake calipers §1.p8

    Example of a sufficiently narrow presentation topic, and substantive failure mode (brake fade from aluminum creep under high temperature).

  • Carbon nanotubes structural applications (overpromised research) §2.p3

    Used to make the point that the 3-million-psi theoretical strength of carbon nanotubes is unrealizable because of vacancy defects, and that the calculation was done in the 1930s. Buckyball Nobel laureate (presumably Richard Smalley at Rice) gets credit for rediscovery.

  • Iron whiskers (1950s screw dislocation studies) §2.p5

    Counter-example to the "defects destroy strength" rule — iron whiskers grown as single crystals with one axial screw dislocation achieved 2.2 million psi because the dislocation was not loaded.

  • 3D metal printing propeller test for US Navy §3.p2

    Stainless steel propeller deposition trial. Surface tension drove a defect on the edge to propagate and grow. Used to illustrate why metal surface tension (10× higher than other materials) makes 3D printing of metals hard.

  • Manganese aluminum bronze electron-beam 3D printing trial §3.p3

    Better-wetting alloy, deposited in circles with electron beam. Shows acceleration humps at scan reversals (Newton's laws) and residual-stress problems despite better surface-tension balance.

  • US Air Force turbine vane repair program (DAABER) §3.p5

    The "dabber" — arc welding machine to rebuild worn turbine vane tips. Five-hundred-dollar vane, couple hundred dollars repair, three thousand more hours of life. Ten-million-dollar automated machine in Oklahoma City repair facility making fifty million on the blades. Used to argue that we have been doing additive manufacturing for eighty years on high-value-added parts.

  • POSCO continuous caster roll refurbishment §3.p8

    Twelve-foot, foot-diameter caster rolls refurbished by lathe-cutting damaged surface, preheating to 600–800°F with flames, and laying down weld metal. Stress relief happens in-process from flame temperature. Used as another long-standing example of industrial additive manufacturing.

  • Turbine blade electron-beam repair and preheating §3.p9

    Hot-section turbine blade tip repair by electron beam, with preheat to 1000°C / 1800°F to prevent nickel-superalloy cracking under thermal stress.

  • MIT Commission on Industrial Productivity - Steel Industry Study §5.p1

    Tom was a commission member, did the steel industry section. Dertouzos chaired (CSAIL head), Lester, Solow (Nobel laureate). Book *Made in America* — opening line: "to live well a nation must produce well." Frames the productivity-vs-competitiveness teaching unit.

  • 1984-1985 Japan Manufacturing Study §5.p2

    Tom's sabbatical in Japan, walking through factories and research labs. Concluded they weren't more productive — they were more competitive because of the 240 yen/dollar exchange rate.

  • General Motors 1980s automation and competitive decline §4.p6

    GM VP big on robotics, spent fifty billion in the 1980s automating — same fifty billion that could have purchased Toyota if Japanese law had allowed it.

  • China rare earth embargo on Japan §7.p3

    Canonical political-externality case. Chinese de facto monopoly (90% of world production), embargo on Japan, MIT faculty response funded to develop clean rare-earth extraction.

  • 1973 Arab oil embargo §7.p5

    Two-dollar-a-barrel oil, embargo, screeching halt, four-or-five-hour gas lines. Industry responded by 1978 with fuel-switching capability, so the 1978 and 1982 embargo attempts failed. Frames political externalities and infrastructure response.

  • Tank explosion at Pennzoil Oil City refinery §8.p1

    Forensic consulting case ca. 1995. 1920s riveted storage tanks, oil-saturated tank farm ground. Tom figures out at breakfast that Pennzoil keeps the refinery running not for production economics but because shutting it would trigger EPA cleanup assessment. Used to illustrate economic externalities.

  • Flint Michigan lead in drinking water §8.p5

    Mentioned in passing as current news (Spring 2016) to introduce lead as a social externality. Pivots to Tom's own house renovation to remove lead paint.

Layer 2 — cleanup edit
p1 00:00

Yes, if you don't, it's okay by me. Okay, and I've, you know, I've had two or three graduate students that, they really want me to give me a deadline, but that's not the way. Okay, I mean you're here to learn to be a professional and you should act like a professional. My father taught me when I was five years old, if you're old enough to be an adult you should act like an adult, and he held me to that standard when I was five years old. Okay, my older brother didn't do so well to that standard. He had fights with my father, but I found it was just easier to get it done.

p2 00:33

In fact, the way I learned not to procrastinate, he'd say to my older brother, well, have you done such and such — some assignment he'd give him — my brother'd say no, and he'd get upset with him. And when I was about seven or eight, he would come to me and he did the same thing, have you finished such and such? I said yep, all done. And he would never congratulate me or anything, but I could tell that he was pleased to know that I had done what he asked me to do. And so, you know, I reacted positively, my brother reacted negatively to the same inputs. But anyway, so I'm in favor of not procrastinating, get it done early.

p3 01:13

And I know people who say, who I do my best work when I'm under pressure, and I think that's just absolute fallacy, okay. I don't think anyone does the best work when they don't have time to do a good job, okay. I think that's an oxymoron, but anyway, that's another story.

p4 01:31

Okay, let's talk a little bit about the presentations. Are we on, exit. Okay, so on the presentations, the presentation should be limited in scope. I don't want you to come in and spend ten minutes telling us how to solve world hunger. I don't think that's really going to be enlightening for anybody. I mean, you can get those types of stories out of the Wall Street Journal, okay, and they're worthless, they're not worth reading.

p5 02:02

And in fact I did give a couple of B's last year because the people came in and gave me stories like that. In fact, one of them did a story and just paraphrased what they read in the New York Times about composites and ultra lightweight composites in Boeing aircraft. And at the end of the story they sort of admitted they would never use these ultra lightweight composites because they were too expensive and they had no structural integrity. I mean they were so lightweight that they just collapsed, okay, things like aerogels. Okay, if you know what an aerogel is, okay, it's got a density half that of water, okay, and if you blow on it, it will collapse. It's sort of like, you ever seen kids play with making soap bubbles? It has about the structural integrity of a soap bubble. Put any stress on it and it collapses.

p6 02:52

Okay, and they came in and they told us this wonderful story about how aerogels were going to take over the world. This is an article from fifteen years ago. I said, and so are they using them? Well, no, not yet. Okay, what do you mean no, not yet? You just told us this was the material of the future, wonder material. I didn't say that to him in class, but I did give them a B.

p7 03:17

So I want something of substance, and I think that goes without saying, you're at MIT. I don't want it to be too general. For example, using my own talk yesterday about 3D printing, I didn't do 3D printing in general or additive manufacturing in general, I did 3D printing of metals. And if you actually went through the outline of what I did, I could have given you a PowerPoint presentation of that in ten PowerPoints, and you know, cover things like — I could have done Prandtl number, Bond number, and what was my other dimensionless number, anyway, whichever one it was — on one overhead, right, and said these are the properties of metals, and talked about what are the limitations of doing 3D printing of metals. Okay, that's something of some substance that hopefully most of you didn't already know about, and so you learn something from it. And that's what I want from you, okay. I took fifty minutes, but I'm the professor, I have a certain literary license. No, actually I had to explain a few things along the way.

p8 04:25

And when you're doing a presentation, you don't have to explain everything. That's what questions and answers are for. Okay, you're just trying to introduce the topic to somebody. Any questions on that? So don't tell me about use of composites in automobiles, that's a little broad, okay. If you want to say use of aluminum-silicon-carbide calipers for lightweight brake linings for disc brakes, okay, great, that's specific enough, and I'm sure you can get down to why they do it or why they don't do it.

p9 05:00

That is actually an example from twenty-five years ago. People were all excited about using aluminum-silicon-carbide composites for brake calipers and they found everything was fine until you hit the brakes very hard. The aluminum heated up and crept, and all of a sudden your calipers no longer had the same shape, and then they wouldn't squeeze the brakes anymore. Minor problem, the brick called — brake fade, you know, hit your brakes hard three times in a row and you have no brakes, and you never will have brakes, you're going to have to replace your brakes because they just deformed out of shape. Anyway, so little things like that.

p10 05:36

And actually, so if I remember and I have time each day, I will try to give you my sound bites from the day before. Here are my sound bites from the day before. I wouldn't have expected any of you to be able to generalize what I talked about 3D printing to come up with these types of things. But one of them is material selection, which is what this module is supposed to be, is a multi-dimensional problem. Okay, people say, why don't you just do 3D printing of metals? Well, there's quite a few reasons, and I spent a whole hour going through a lot of the reasons. And hopefully you realize it's a more complex problem than you just substitute plastic for metal in your 3D print head. Okay, it's more complex, and it involves mechanical and melting problems, and I organized it in that way and stuff. So it's multi-dimensional problems. Most things we're going to talk about in material selection are multi-dimensional, okay. You can use a material, dig it out of the ground, sometimes the biggest problem is recycling it, okay, for example. And people not always think about that.

p11 06:43

We also talked about Ashby plots, and Ashby plots basically tell us there are limits to material properties. You can't just, you know, we'd love to have a material that has a strength of 5 million psi. Anybody know why we can't do that? We can't do it, by the way the strongest material we can get is about 3 million psi, and that has to do with the strength of the individual chemical bonds, okay. If you take what's the strongest bond in the world — all you chemists out there, none of you are chemists — oh, it's okay to answer, guess. Most people say carbon, because that's what we have in diamond, which is the strongest material. It's not the strongest bond. If you're a chemist, it's a silicon-oxygen-silicon bond, okay. I actually told you that yesterday, but you didn't remember it because I told you that silicone rubber had the highest melting temperature of any of the rubbers, 500 degrees, and it's because that backbone of silicon-oxygen-silicon, as opposed to the Kevlar backbone of carbon — the silicon backbone is actually stronger than the carbon-carbon bond.

p12 08:01

And if you actually calculate what the strength of that bond is going to be, you'll get about 3 million psi. And you know about this because you've read in the New York Times and the Wall Street Journal all about carbon nanotubes, right, and they have a strength of 3 million psi. Well, that's a calculation that was done in the 1930s when we first learned quantum mechanics and they actually learned something about the bond energy. And I think if you take my solid state welding course, I spend a half a lecture going through this type of stuff. But basically we're limited in our material properties by the strength of the chemical bonds between the atoms, okay. There's a fundamental limitation. You can't get a material with the modulus higher than 60 million psi. I can't remember, what's that, 200 — it's not 200 gigapascals, about 400 gigapascals if you're metric, whatever it is. But that's limited by the strength of the chemical bond. Unless you come up with some new elements that have stronger bonds, we're not going to get anything any stronger.

p13 09:05

And what's the problem with the 3 million psi of carbon nanotubes, anybody know? Actually I told you that yesterday. It's the fact that we have defects. I've told you about fracture mechanics and Griffith and little notches can weaken the strength of things. Well, I think I told you the Bob Spray quote about material scientists know it's defects that control properties, okay. And a perfect carbon nanotube would have a strength of 3 million psi, but is anyone in here know of anyone who's ever measured that? Well, how do you grip a little carbon nanotube to measure the tensile strength? And if you did, you would find it probably has about one tenth of that strength. And the reason is, there'll be vacancies in there. In that perfect little carbon nanotube there's going to be a missing carbon atom. Any temperature above absolute zero, thermodynamics tells us, the entropy tells us that we're going to have a vacancy. And if you have a vacancy, that's a defect in that carbon nanotube, and that will create a stress concentration and it will be much weaker, maybe ten times weaker. So all of you that are out there working on carbon nanotubes for structural applications, you'll get a thesis out of it, you just won't get a useful product. Okay, because we've known these things for sixty years.

p14 10:23

But some physicists down at Rice University, who thought he should win the Nobel Prize — actually I think he did, for discovering buckyballs — did the calculation that had been done in the 1930s, and he took credit for it. So I've discovered a new material that is going to be ten times stronger than anything else we have. Well, you know, in the 1940s we actually measured iron whiskers that had strength of 2.2 million psi, and we got around the defects of the dislocations because the iron whisker was a single crystal with a screw dislocation right down the axis. And so when you pulled on it there was no stress on the dislocation, if you know anything about dislocations and Burgers vectors and things like that, and you got 2.2 million psi. A student about twenty years ago, so how do you do that calculation? I'd explained how you would do it, and then they kind of challenged me. So I went back to my office, in five minutes later I'd scratched it, I got 2.2 million psi for the strength of iron. It's just the strength of the chemical bond between two iron atoms. It's a calculation that was done ninety years ago. But this guy twenty years ago discovers buckyballs and wins the Nobel Prize because he goes around in the press, I've discovered a new material that's going to revolutionize the world. Okay, he discovered those twenty, twenty-five years ago. Have buckyballs revolutionized your world in the last twenty, twenty-five years? Don't think so. Okay, but actually it has for all of you that are doing research, there's a lot of research money to study this.

p15 12:10

Anyway, so there are limits to material properties, and we're going to talk about those limits in some more detail, okay. So that's the summary. And now I've gone through twenty-five percent of this lecture just summarizing the last lecture, but hopefully pointing out some other things.

p16 12:27

I did want to finish up this stuff on why we don't do 3D printing of metals. And here is, I will pass this one around from Dr. Belmar, which is this five-hundred-dollar part, laser printed. I'm sure it took hours, he didn't know how long, but I'm sure just knowing the solidification process of thin layers, that part took hours to produce. And that's why it costs five hundred dollars. So you can 3D print metals, not very economically, but you can do it. And if you're talking about something's going to go in outer space, that's great. [Tom passes around a laser-printed metal part.]

p17 13:04

And I told you about, things we were trying to make propellers for the Navy so they wouldn't have to buy castings and let them sit in a warehouse for a year in case the propeller broke. We tried to do some stainless steel just because it was easy, we were doing simple geometries. And what happened, I told you about the surface tension problems and what happened here. You can see on the edge we started to get some imperfect melting, and that defect propagated and got larger and larger because of the surface tension, okay. You see the first part of it gets a little wavy, but it didn't look too bad. But all of that is due to the surface tension of metals, which are ten times higher than the surface tension of other materials.

p18 13:49

I don't think — did I pass this one around? This one I think I may have passed around. This is, think about a hundred — it's actually a pretty good deposit. You'll see some little humps on either end because you scan this way and start scanning back that way, and there's a delay as you go from a finite velocity in that direction and then you have to accelerate in the other direction. And so you actually build up a little more material on each end, and that's just because of Isaac Newton, and you can't make an infinite change in speed.

p19 14:17

But to answer this question of what — yeah, yep, it's just a wire of manganese-aluminum-bronze welding wire, it's a tube, think that might be manganese-aluminum-bronze tube, and we just went around in circles, okay. Now we did it with an electron beam for reasons of the Bond number and the high heat transfer coefficient you need to solidify metals, okay. The manganese-aluminum-bronze actually has a better wetting surface tension balance than some of these other things. You can see we were reasonably successful with that, although we're going to still end up with tremendous residual stresses. That answer the question? Okay, so yeah, it's just a fairly simple process.

p20 15:10

So I was now going to tell you the question that was posed to me by Technology Review editor was, why don't we do 3D printing of metals? And at the end of my spending an hour with them, I said, but in fact we do, and we have been for eighty years, okay. For example, the US Air Force about twenty-five years ago decided they need to build the tips of turbine vanes. And these turbine vanes which go into a jet engine basically are spinning around and they get hot with time and they creep and get a little longer, and so they wear out the edge, the top edge. They want to rebuild them, the thing is still good for another three thousand hours of use. So they built a little machine, a little arc welding machine, they called it the dabber, and they would build up the edge and then they would machine it back, and they would redo the edge, and then they'd remachine it. Well, you're talking about a vane that might be worth five hundred dollars, you can afford to spend a couple hundred dollars to repair it if you're going to have a brand new vane, right? So high-value-added part, high heat intensity, very limited geometry. I don't have one, but I've seen these things where they grew the thin vane like this. I've got two different sizes, by an extra quarter of an inch, and then reaming and disonate, and it's not critical, it's not a lot of stress on it in service, as it's the tip, the big stresses are down at the base where you have the biggest centrifugal forces. The tip doesn't have big centrifugal forces.

p21 16:51

So there's an example of something. The Air Force automated it in their Oklahoma City repair facility, it's a ten-million-dollar machine to do it because they have all that precise alignment and control and everything else, costs money. But they were going to make fifty million dollars with the blades on a ten-million-dollar machine, you could advertise it.

p22 17:18

Okay, so we have not solved the problem of 3D printing of printed circuit boards, but we have done things that for eighty years. There's a billion-dollar industry out there called thermal spraying where we repair old worn-out parts. Companies like Eutectic Castolin is a four or five hundred million dollar a year company, and they make all kinds of metal powders and they put them in a flame, and you take a piece of metal and you flame spray, you thermal spray this powder on top of the metal. You might melt it, in which case you probably are going to have to preheat that thing to a very high temperature, okay, because of some of the things we talked about. But they've been doing weld repair, basically thermal spray repair of parts, for eighty or ninety years. Usually nice circular parts or flat parts, not complex geometries like 3D printing, but we have been building things up by additive manufacturing for years and years.

p23 18:20

Visited POSCO Steel when it was the largest steel company in the world. Well, the largest steel plant in the world, in Pohang, Korea. They took me through a facility where they refurbished the rolls for the continuous caster of the steel mill. These rolls are about twelve feet long, about a foot in diameter. A molten band of hot steel comes down out of the casting machine, which is about seven or eight stories tall, and it gets bent 90 degrees, and these rolls — and there are hundreds of them — are bending this hot steel. Well, they wear out, I mean they're touching steel bits at above a thousand degrees centigrade, and there's a lot of wear. Rather than throw out these rolls, which are actually water-cooled in service, but the surface is touching something that's basically 1200 degrees centigrade, they'll get thermal cracking on the surface and things. So they'll take them into the shop. And this shop was about half the size of a football field, okay, and they just had lots of lathes. They'd have this twelve-foot-long roll and they'd do a pass and they'd cut off the bad stuff on the surface. And then they would preheat the whole thing. I mean there were flames all over the shop, I think I was there in August, it was pretty hot, okay, and just great big flames preheating these things to six, seven, eight hundred degrees Fahrenheit. And then just laying down weld metal. They got around the residual stresses because they're welding, and with the flame temperatures they're stress relieving as they go. But they're building up, you know, 28 — massive metal on the outside of these rolls. But they got to replace these rolls periodically, probably after two weeks of service, and this machine is going to run continuously for two or three years, okay. So you have to replace them and stuff. So hey, we do lots of buildup of metal parts.

p24 20:19

There's another example I was thinking of. Oh, another, fancier turbine blades, not those, but the ones that are in the hot section of the engine, I've seen two places where they're doing electron beam adding the tip or something, melting in there, and they're preheating to a thousand degrees centigrade, 1800 degrees Fahrenheit, because of this problem of sucking out the heat and the fact that the alloys, the nickel-based superalloys, is very prone to cracking. So if you have big thermal stresses, you're going to get cracks. So what they do, they preheat it up to within a couple hundred degrees of the melting point, okay. So we do it, it's just a little tricky and it's a little bit expensive, and you don't do this on twenty-seven pound parts, okay, you do it on very high-value-added parts.

p25 21:11

So 3D printing is a wonderful technology. Nanotechnology is a technology — I won't use the word wonderful with it, but it's a technology then is oversold.

p26 21:25

So let's talk now, start after two and a half hours, start actually talking about what we're going to do in this course. Lecture 1, which will start today, is on externalities. And then we'll go to price, costs, and abundance, and talk about limits of properties, which we've already talked about. We're going to talk about materials manufacturing productivity, spend a fair amount of time talking about productivity of different materials, steel, aluminum, composites. You're going to hear the word steel a lot in this course. In fact, usually the students after about two or three days of lectures will start making jokes about all he ever talks about is steel. Well, you're going to find out why in a little bit. There's going to be some statistics on steel that will probably surprise you.

p27 22:17

Nonetheless, let's talk about productivity and competitiveness. Does anyone know the difference between productivity and competitiveness? I'm going to make this an economics course, sir. Yeah, exactly, yep. It's relative and it involves things like price of labor in one country versus another, right. Productivity is how well can you make something, and it's sort of independent of things like labor rates, yen-dollar exchange, yuan-dollar exchange. You know, those exchange rates are all part of competitiveness. Can the Japanese make something cheaper than the Americans, can the Indians make something cheaper than the Americans, okay, at equal quality or whatever, okay. Competitiveness is a huge, all-encompassing issue. Productivity is how efficiently can you manufacture it, usually measured in person-hours per ton, or person-hours per gram, whatever, okay, some amount of effort per a quantity.

p28 23:37

Okay, now it turns out, back in the — before you were born, in the mid-1980s, the Japanese were eating our lunch, okay. Something like seventy-five percent of Japan's workforce was involved in something that had to do with exporting. And the Japanese were selling Toyotas here that were better quality than any of the GM junk that they were producing. Then GM's improved significantly, and there are a number of books that were written about this. One of them was, what's his name, Dan Roos's book — he was the second author — of a book called Lean Manufacturing. You've all heard about lean manufacturing, term coined by a professor in civil engineering here who is expert in the automotive industry, okay. I remember Dan Roos twenty years ago was personal friends with the CEO of every major automotive company in the world, okay. He was sort of a specialist on automotive manufacture. And he did a study of why Toyota was eating our lunch, and he pointed out they were using lean manufacturing production technologies, which is now a very common, very big buzzword, but in the mid-1980s it wasn't.

p29 25:06

In the meantime, mid-1980s I was a young professor, I probably wasn't even a full professor at the time, and a guy named Jerry Wilson was the Dean of Engineering and he was very concerned about the declining productivity of America, the American industrial sector. And people were looking at the amount of employment in manufacturing in the United States and it was just decreasing. Back in, like, 1980, it might have been over twenty percent of the workforce in the United States was employed in manufacturing, high-value jobs, United Auto Workers. These people made enough money to be able to buy a home and a car and send their kids to college and things like that. And the workforce was decreasing, okay.

p30 25:55

It turns out there was a guy at General Motors who is the vice president, he was very big on robotics. He was going to eliminate all the hourly workers at General Motors, okay. He didn't like — the General Motors always despised the hourly workers, and it was sort of a mutual distrust between the two, and they had terrible labor fights and whatnot. These are some of the externalities that go on. And it turns out this guy, he used to — in the, this is before we had PowerPoint and all these other things — I used to see some of his presentations, he would have $50,000 audiovisual presentations on what General Motors was doing with laser manufacturing and things like this. Turns out during the decade of the 1980s, General Motors spent fifty billion dollars automating their manufacturing facilities, okay. Did you know that in the 1980s, if it had been legal in Japan to purchase Toyota on the stock market for a foreign company, General Motors could have purchased Toyota for fifty billion dollars, okay. But they couldn't because the Japanese laws — that's another externality, Japanese laws wouldn't allow an American company to go purchase stock of a Japanese company in Tokyo or in Japan.

p31 27:16

Anyway, the Japanese reading [eating] our lunch, and so Jerry Wilson commissioned a book that was written by Michael Dertouzos, who was head of CSAIL, computer science lab, almost became president of MIT. Michael's passed away now, but he was a Greek, he was a consultant to the premier of Greece. I remember Michael, they were complaining at Engineering Council once about the assistant professors didn't make enough money to live on in the Boston area, and he said, well let them go out and consult, I can make twenty thousand dollars a day. I said what? Well, that's what Michael was making, that kind of money, okay, as a consultant, you know, consulting for the government of Greece. Richard Lester is still around, Bob Solow won the Nobel Prize in economics. Anyway, these guys were asked to be part of a commission, MIT Commission on Industrial Productivity of the mid-'80s, and they did, and they wrote this book. I was a commission member, and did something on steel productivity in the steel industry.

p32 28:25

And this is the opening part of the book, and I've highlighted the first sentence: to live well a nation must produce well. And that's what the whole book was about, why was the United States not as productive as Japan, okay, in manufacturing. Well, I'd spent my sabbatical in 1984 and '85 in Japan. I had walked around these factories and these research labs, and they certainly didn't seem like they were as productive as the American factories that I went through. And it turns out they weren't. They were more competitive because at the time the yen-dollar exchange, when I was renting my home in Tokyo, the exchange rate was 240 yen to the dollar. What is it today? I know, about a hundred yen to the dollar.

p33 29:17

So what had happened in the 1980s is, the Japanese, the Toyota wanted to sell in the United States because we were the world's market. We were one third of the world's gross domestic product, everybody wanted to sell in the United States. So Toyota was manufacturing cars in Japan, they were doing a wonderful job of manufacturing, lean production, and they were shipping in the United States. And Ronald Reagan in the meantime was doing Star Wars, he was going to defeat the Soviet Union. And he did, he defeated them economically by bankrupting them. They couldn't keep up with all the money we were spending on Star Wars. It was a big defense initiative, right, and eventually the Soviet Union fell apart in the early 1990s for economic reasons.

p34 30:07

In any case, the Japanese were loaning us money, so — and we were running huge deficits in the federal budget that we never ran before, because Ronald Reagan was going to defeat the Soviets, he was going to outspend them, and he did. And the Japanese were loaning us money at 240 yen to the dollar so we could purchase their Toyotas, and we did. And they were better cars than General Motors, and there was a big upheaval. And it turns out eventually we had to pay the piper, and we are now paying the Japanese back at a hundred yen to the dollar. So we're taking our sixty percent discount, because the Japanese thought they could just suck up those dollars and keep on hoarding dollars, and except it doesn't work that way.

p35 31:04

There's another country that's doing that right now. What's that country? No one knows who's doing all the manufacturing in the world, where everything you get says Made in China? And anybody heard anything, fights about the yuan-dollar exchange rate? And it turns out the Chinese have trillions of dollars, trillions of dollars. And now they're finding, you can't eat dollars, okay. You might be able to buy something with dollars, but I mean they just don't taste good, okay, those dollars. And so now eventually they're going to have to let the yuan float in the international currency, and we will be paying the Chinese back. All these VCRs and all these things we've been buying from them, we're going to pay them back twenty cents on the dollar, okay. And they're not going to be happy about, they're going to get twenty cents on the dollar for the trillions of dollars worth of goods manufactured and sold us, okay.

p36 32:19

There's only one country in the world that can do this, it's the country that is the country that's currency is the market for energy. The price of oil is denominated in dollars around the whole world. Whoever controls the dollar is defining the world's currency, and everyone else has to adjust to where we're the reference point, okay. And you're seeing this right now. Europe's being deva— the European currencies are being devalued with regard to the dollar. Why? Well, it turns out, to live well a nation must produce well. Which country has had the highest manufacturing productivity rate for the last hundred years? The United States. We are the most efficient producers, even in the 1980s when we were buying Toyotas to build Star Wars and to buy and drive the Toyotas, and the Japanese were loaning us the money to do it. We still had better productivity.

p37 33:33

And why were we building Star Wars and the Japanese were building cars and someone else in Taiwan was building whisk brooms or whatever? Anybody know the economic principle behind that? It's called the law of comparative advantage. If we both can make something, let's say we can both make a computer, but I can make it faster and more productively, less cost, than you can make it, but if I can actually make the computer chip better than you can, and comparatively five times better, I can make the computer chip, I'll let you assemble the computers. We can both do it, I could do it, but I'd rather get the comparative advantage of making the high-value part, the chip that goes in it. Or I'd like to be Boeing, I'd like to get the high value of assembling and designing the aircraft, and I'll let you build some components that I'll stick on in my factory. But the law of comparative advantage is, I'm going to take the high-value stuff, I'm going to leave you the lower-value stuff. If you take an economics course, it's the law of comparative advantage.

p38 34:55

We have the highest productivity in the world, and we always have for the last hundred years. Now we stole it from the British, who had it in the industrial revolution, okay. But we have the highest manufacturing productivity. Why has manufacturing employment been going down for the last fifty years in the United States? Because our productivity has been going up. Everybody thinks, because if you read the Wall Street Journal, we're losing our manufacturing competitiveness, all the jobs are going offshore. The jobs we don't want are going offshore. We're exporting our pollution, let the Chinese make the stuff that pollutes. We want to have nice pretty views, we want to walk through clean air, we'll let them choke on their smog, okay. This is what we do because we have been the world's dominant productivity king for a century. And the world buys its energy, and energy is the thing that determines cost of things in general in dollars. And whoever has the gold rules, okay, the golden rule. We have the dollar, and as long as we keep our productivity up.

p39 36:18

Does it well — I actually used to give a talk on this. At the time of the American Revolution and Constitution and George Washington, anyway, anyone have any idea how many people were involved, what fraction of the workforce was involved in agriculture in seventeen ninety? Seven percent? Ninety-seven percent. Ninety-seven people out of a hundred were just toiling away to make food, and ninety-seven percent of, they made enough extra that three percent of the people could be George Washington or Thomas Jefferson or Ben Franklin. But those people were in the minority. Today, well, actually if I went back to 1980, how many people, what fraction in the United States population was working in food production in 1980? Three percent. We had a thirty-fold improvement in two hundred years in productivity in food production, which is a pretty basic need, okay.

p40 37:28

What fraction is it today? It's about one and a half percent. We're losing those farm jobs, haven't you read that in the Wall Street Journal, right? Rural America's, they're all moving to the cities. Why? Because the law of comparative advantage, it says, hey, you might have been able to live for free on the family farm, but you can come here and pay twenty-five hundred dollars a month for a two-room apartment, right? That's productivity, well, that's competitiveness. But in any case, to live well a nation must produce well is the beginning of Made in America. And it's Paul Krugman — who's Paul Krugman? He's an economist, he started at MIT, went to Stanford, won the Nobel Prize, now he's at Princeton, okay. Another one of these people that Lester Thurow was talking about, they tend to hire our extinct volcanoes. But as Paul Krugman says, he's right, productivity isn't everything, but in the long run it's nearly everything, okay.

p41 38:27

So what are the things that determine productivity in materials selection and economics and stuff? Well, there are externalities. Anyone taking an economics course, anyone know what an externality is? Okay, an externality, right out of Wikipedia which is the source of all knowledge, right. What do they do here? Oh, that's not it. Yeah, to figure out — anyway, I just have to read it without blowing it up. In economics, an externality is the cost or benefit that affects a party who did not choose to incur that cost or benefit, okay. Something external, like air pollution, okay. All the rest of us have to endure air pollution because someone designed and built these trucks that are dirty. [Tom fiddles with the projector.] Same thing, figure out, well, let's not worry about it.

p42 39:37

So the externalities, there are lots of different types of externalities, and let's talk about some of those. Political — there are political externalities. Rare earth metals. And what's the story with rare earth metals? What's the political externality of the last eight years? What happened on rare earth metals, and why are rare earth metals — well, Mendeleev — important? Production methods — we export our pollution, right, so let someone else breathe that air, okay. Rare earth metals, you ever heard of neodymium-iron-boron magnets? Neodymium is a rare earth metal, okay. Samarium-cobalt are magnets. Rare earth metals are functional materials, [not] really structural materials, but functional materials used in many high-value applications.

p43 40:52

And no one remembers, well, maybe you were in elementary school at the time, but about eight years ago or so, turns out China has tremendous rare earth metal reserves. Now they're not really that rare, it's a misnomer. The United States has tremendous reserves of rare earth metals too, but China has lots of rare earth ores. And it is a very dirty process, you think you're in the Black Hole of Calcutta, okay, to go see a rare earth metal plant. People died at an early age who do this, because they do it by technology that's a hundred years old. In any case, the Chinese had dropped the price because the law of comparative advantage. We had produced rare earth metals back in the 1970s, 1980s, but the Chinese — as China opened up after Richard Nixon opened up China, the Chinese decided they had all these reserves of rare earth metals, they had cheap labor, they weren't worried about the pollution at the time, and they could produce rare earth metals at some cheaper than anybody else. So all the American mines and factories shut down because it's a dirty industry and they're going to get fined by the EPA anyway, so send it to China, let it go to China.

p44 42:08

And the Chinese, all of a sudden they're producing like ninety percent of the world's rare earth, and they decided they were having a fight with Japan. And who needs all these rare earth metals in their magnets and their batteries and things? The Japanese, for their consumer electronics. It's replaced automobiles as one of the big high-value export industries in Japan. And so the Chinese just decided we're not going to — we're going to put an embargo on, and we're not going to ship you any rare earth metals. And the Japanese government and the companies went berserk. They were going to be shut down because they couldn't get this critical material. It wasn't rare, but it turns out the Chinese had a de facto monopoly because everyone else had gotten out of the business. So for the last six or seven years half the faculty at MIT that are working on materials are dabbling in some way to produce rare earth metals by a clean technology, so that the next time the Chinese pull this stunt, okay, we'll be ready to come in and do something.

p45 43:22

Same thing happened in 1973 with the Arab oil embargo. We were all buying two-dollar-a-barrel gasoline. Oil, crude oil, was being pumped out of Saudi Arabia for two dollars a barrel in 1972, and all of a sudden the Arabs got together and they said we're not going to ship you any more crude oil. And all of a sudden the world economy came to a screeching halt in many areas. The price of energy shot up, there was the oil crisis we called it. My wife and I would, and everybody else would, sit in line for four or five hours waiting to fill up our gas tank. So all these cars are running their engines sitting there in lines that are a hundred yards long to get up to the gas pump, okay. It's wonderful, okay.

p46 44:16

Same thing happened, they tried it again in 1978, by 1978 it was nowhere near as effective because all the American industry said we're not going to let you do that to us again. We're going to be able to use natural gas or oil, and we'll just be able to flick a switch. American industry spent millions of dollars to be able to just flick a switch and change from firing those electrical plants with oil or gas. And so the next time they had an oil embargo, we'll just switch. Yes, price of gas went up, price of oil went up, but nowhere near as big a disruption as it had been in 1973, okay. Try to then in 1982 wasn't so effective.

p47 45:00

And now forty years later, Saudi Arabia decided they didn't like all the other oil cartel folks cheating on them. Saudi Arabia can pump twelve million barrels a day at a production cost of five dollars a barrel, and they were selling at a hundred dollars a barrel. They were very wealthy. Well, now they decided we're not going to keep losing market share. They were at nine or ten million barrels a day, and every time they had a little price increase in oil or whatever, or glut of oil, the Saudis would lose market share because Nigeria would just keep pumping. They're corrupt in Nigeria, one of the most [corrupt] countries in the world, and they would just keep pumping. They would violate all the cartel quotas, and they would, because their production cost is about ninety dollars a barrel. And finally Saudi Arabia says, we're going to shut down those frackers in the United States and we're going to put Nigeria out of business because they've been cheating on us for the last thirty years. We can keep pumping oil all the way down to five dollars a barrel and make money. Nigeria, they're hemorrhaging in Nigeria now at ninety dollars a barrel with a price of thirty dollars a barrel. How'd you like to be in Nigeria right now, okay? All those sins of the past are coming back.

p48 46:23

But we're sitting there, and it turns out our — you might know what our frackers' marginal production cost is. The marginal cost, once you've already built, drilled the well and everything else, is down slightly less than thirty dollars a barrel. So they can barely make it right now, but they can make it. They can't drill a lot of new wells, but the Saudis have not driven them out of business yet. They will eventually drive some of them out of business. Anyway, so there are political externalities. It have nothing to do with the technology of buying a particular type of oil or product or whatever.

p49 47:06

Economic — I remember I had an explosion, someone was welding on an oil storage tank in Oil City, Pennsylvania. Oil City is just down the river from Titusville. He might know what Titusville, Pennsylvania is famous for. Edwin Drake discovered oil in 1857, okay, he drilled for oil. Before that, the only oil one had was bubbling up out of the ground up in North Slope of Alaska or the oil sands in Alberta, that's where oil is right on the surface. But Edwin Drake actually drilled for it, he found it, rather than drilling for water. And they built a refinery there and around 1890s in Oil City, Pennsylvania.

p50 47:54

And they had an explosion and killed someone, I had to go out there. And so this was like 1995, and I go to Oil City, it's not the easiest place to get to. And the first time there, it didn't make any sense, old riveted 1920s storage tanks. The tank farm had about two or three inches of — well, two or three feet of gravel, if you dug down about one foot you'd strike oil because for the last hundred years they've been spilling oil from the tank farm, and so the ground was saturated with oil. And it's a small production facility. To me, like, a thirty-thousand-gallon storage tank — you go down to Houston, some refinery, there's going to be a hundred thousand gallon storage tank. Why were they in that night — does anything, why can Pennzoil keep — why is Pennzoil keeping this plant running, it makes no sense economically?

p51 48:51

Well, it made perfect sense economically. I figured it out the next morning at breakfast for myself. They couldn't afford to shut it. Because as long as they were operating, the EPA had no control over them other than they could keep them from polluting anything off their premises. But the law is such that if you're an operating facility, the government is not going to touch those jobs. It's when you shut the plant that the EPA comes in, and you're no longer protecting jobs. They will come in and they will assess you billions of dollars in cleanup costs. So Pennzoil was keeping this inefficient refinery operating in 1995 because they couldn't afford to shut it, okay. It was a loser, money loser. But if they shut it and put all these people out of work, it would be a humongous money loser because the EPA would make them clean it up.

p52 49:47

Now since then they have shut it, it's too inefficient, and they do have to clean it up, and they're cleaning it up, but the rules have changed over the years. Do you know how they used to get the oil from Titusville, which was just up the river, down to Oil City? Just floated it on the river and skimmed it off at the other end, okay. Nowadays you see an oil sheen on the water and the environmentalists are out there to put you in jail as a felon, okay. But back in those days there was no fish in that lake, in that river, okay, they were all — it all had oil for dinner, okay. So Oil City, Pennsylvania, and Pennzoil. Sometimes the regulations will not let you choose the best material.

p53 50:38

Social — okay, social externalities. Lead, what do we know about lead? Well, Flint, Michigan is in the news, but lead — I just had my house and gutted, my wife and I rented a house down the street ten houses down, moved in October, we've lived in this other house for thirty-seven years. Last week they came in to start the construction. You go through my house, you can see the studs, you can see the outside walls. I'm ripping out all the plumbing, all the wiring in this ninety-year-old house, I'm going to rebuild it, okay. I wanted to get rid of the lead paint, okay, because one of these days that old house, built in the 1930s, they're going to come by and I'll never be able to sell that house, it's got lead paint. And some environmentalists going to say you can't sell a house that has lead paint. Well, the rules were different in 1938, okay. But there's no lead paint in that house anymore, it's all in the dumpster, okay.

p54 51:28

Mercury, where's mercury used? Used to be used in lots of things, but there's mercury all over this room, look at the fluorescent lights, every one of them has an arc igniter that uses a little bit of mercury. And why can't you dispose of a fluorescent light in the regular old dumpster? Because it's got mercury in it. And so for environmental reasons we try to get rid of mercury. Diamonds, okay, there's social reasons, the diamonds, blood diamonds, I mean, they're making movies about this stuff now, right. So there's all kinds of things. We're running out of time, I'll talk about some of the other externalities tomorrow, but there's all kinds of social.