Baseball bat aluminum alloy development

Scandium-aluminum at 0.1% scandium doubles alloy cost but increases strength 10–15%. Boeing can't afford it; baseball bats can. Hundred-thousand-ksi-strength bats. ## Figures referenced (recurring numeric anchors, not cases)

I'll tell you what scandium could be used for. If you could put a tenth of a percent scandium in aluminum alloys, you can increase the aluminum strength by 10 to 15 percent. Boeing would love you. But the problem is, to put a tenth of a percent scandium in aluminum doubles the price of the aluminum. It may only be a tenth of a percent. So we actually use scandium — anybody know where we use scandium in aluminum alloys? Baseball bats. You can get a hundred thousand ksi strength in scandium aluminum baseball bats. Anyway, this is relative cost — lots of metrics for these things.

Scandium-strengthened aluminum bats; 100–105 ksi via fine grain size from extrusion-quench process. Trampoline effect requires thin walls to match ball stiffness. Bats now crack after one good hit at the highest strengths.

Scandium, yttrium, and lanthanum are all interesting for ceramics, for functional materials. In some of the ceramics — like yttrium-stabilized zirconia — it can be a structural material. Scandium does go into metals. If you look at my little chart, scandium is at two thousand tons a year. Anybody know what scandium is used for in alloying? Aluminum, right. Anybody know what the highest strength aluminum alloys are, and they're not used for aerospace? 100 ksi strength. Baseball bats.

Scandium is kind of interesting, $4 million a ton, and there's only about 2000 tons a year. Here is one of the largest uses of scandium — well, I don't know if it's the largest. Scandium alloy, 100 ksi aluminum, thirty percent stronger than what goes in the Boeing aircraft wing. It turns out there's a lot of money in baseball bats. That's why, if you add two-tenths of a percent scandium to an aluminum alloy, you've just doubled the price of the aluminum alloy. Scandium is $4 million a ton, which is about $2000 a pound. But scandium refines the grain size like nothing else. The Soviets tried this. They weren't worried about economics thirty years ago, and they showed that scandium can really improve the properties of aluminum alloys. So people are looking to see if they can drop the price of scandium, because it's not a rare element — there's a lot of it out there in the world. It's sort of dispersed; you've got the entropy problem. But some of the Japanese companies — Sumitomo — announced that they will produce a hundred tons of scandium oxide a year. That's what they've announced, and they actually are probably going to produce a lot more than that. People are looking at this to be able to increase the strength of aluminum in automobiles. But you can't just double the price of an automobile lightly.

Tom introduces a scandium-alloyed baseball bat (TH-T 100) and uses the Soviet origin of scandium grain refinement to set up the broader story of scandium vs. titanium/zirconium in aluminum alloys.

At the end of the day yesterday I'd forgotten to bring my scandium baseball bat. If you look on here there are a number of things. One, it says TH-T 100 scandium alloy. It was really the Soviets who came up with using scandium. We use titanium in some aluminum alloys as a grain refiner — you get titanium nitrides or titanium borides that form as low precipitants and keep the grains from getting large, so you get fine-grained aluminum. But scandium works even better.

Tom holds up the scandium-microalloyed aluminum bat case as the highest-strength aluminum alloy he knows of — 100 KSI yield from fine grain size achieved by extrusion-quenching. Limited to ~2 mm wall thickness; bats break and must be replaced; $300-400 retail.

This doesn't give you the 8000 series alloys. 8000 series is sort of a catch-all — that's where your aluminum-lithium alloys are. I'll have to bring in tomorrow one of the highest-strength aluminum alloys, actually the highest strength I know of. Does anyone know what the application is? They would be 8000 series. Baseball bats. Aluminum bats.