Bulk metallic glass golf clubs

Same case-cluster as the BMG commercialization above; cited specifically as a fatigue-life and high-margin-niche case. About 50 shots before fracture.

The only commercial product they've come up with is golf clubs. The metal woods — the same type of thing I passed around for investment casting out of stainless steel. They've been around for about fifteen years. I always say you can sell anything to a golfer. Golfers are a little older, they have a little more disposable income, and they will pay anything to be better than their executive friend down the road, to beat him in a golf game. If they can get some advantage they'll pay thousands of dollars for it. When I was department head fifteen years ago, we were interviewing one of Johnson's postdocs for a potential faculty position. I said, what are the markets for this? He says, well, we've made golf clubs. I said, anything else? He said no. And I just learned about six months ago that they are selling the golf clubs, but apparently their fatigue life is such that they get about 50 shots before it breaks. But you can sell anything to a golfer — 50 shots, that's a whole round. If he beats his buddy, it's worth $10,000. They may have a $50,000 bet on the game, I don't know.

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Bill Johnson (Duwez student, now Caltech professor) succeeded in casting 2–3 mm bulk metallic glasses with ~500 ksi strength and excellent corrosion resistance, but the only commercial product in 15–20 years has been golf clubs — which crack after ~100 shots. Service temperature limited to 300–400°F before recrystallization. Tom's running line: "you can sell anything to a golfer."

All through the 1970s, when I started as an assistant professor, you wanted to get money in rapidly solidified powders or rapidly solidified metallurgy. There were hundreds of millions of dollars, if not billions, because this was going to be the new way — not from the vapor phase but from the liquid phase. All you had to do was figure out how to consolidate those foils or powders into a solid material. How do we do that? We heat things up. You heat them up and all of a sudden the atoms rearrange into a crystalline form. So Bill Johnson, one of Duwez's students who's now a professor at Caltech, played around and made what they call bulk metallic glasses. He can cast things 2 or 3 mm thick and they'll still have the glassy structure of a metal. It has fantastic corrosion resistance, fantastic strength. You can't make anything an inch thick, but you can make it several millimeters thick. You could do a lot of structural things with 500 ksi strength and corrosion resistance.