3D printed amorphous metal alloys show material promise

“Metallic glasses lack the crystalline structures of most metals – the amorphous structure results in exceptionally desirable properties,” said Zaynab Mahbooba, first author of a paper on the work and a Ph.D. student in North Carolina State University’s Department of Materials Science and Engineering.

The fabrication of metallic glass requires rapid cooling to prevent the crystalline structure from forming, which has restricted researchers to casting metallic glasses in small thicknesses. Amorphous iron alloys could normally be cast no more than a few millimetres thick, a limitation called critical casting thickness.

“The idea of using additive manufacturing, or 3D printing, to produce metallic glass on scales larger than the critical casting thickness has been around for more than a decade,” Mahbooba said. “But this is the first published work demonstrating that we can actually do it. We were able to produce an amorphous iron alloy on a scale 15 times larger than its critical casting thickness.”