Amorphous metals development

Dave's extended case study of a 1980s materials cause célèbre. The physics (no grain boundaries → low hysteresis loss for transformers), the splat-cooling origin in Nick Grant's MIT lab in the early 1970s, the engineering breakthrough (sessile-drop ribbon casting on a cold wheel), ten years and $100 million to commercialize, and the disappointing market outcome (~$250M business, mostly Japanese, mostly high-energy-cost markets) as silicon iron incumbents improved their product.

Dave: I've worked on a lot of technologies in my years, some of them sublime and some of them ridiculous. One I did work on was amorphous metals. Amorphous metals were a very big cause célèbre in the 1980-1990 range. It's an interesting concept. As I'm sure most of you know, metals form crystalline structures when they solidify, and the driving force for those crystal structures is thermodynamically very large. The only way that you can create a metallic structure that doesn't have long-range order, that isn't crystalline, is to freeze it very quickly. So in the early 70s here, Nick Grant and others were looking at splat cooling of metals. The way they did that was to levitate a drop of metal — so you need a magnetic field to levitate it, so we focused basically on iron as your primary component — and then blast it with a jet of air or a jet of nitrogen and smash it up against a really cold surface. Splat cooling was what people called it. And with that you could make structures that were amorphous. They were metals but they didn't have long-range order, they weren't crystalline.