Amorphous metals, better known as metallic glasses, are alloys that have a disordered atomic structure. Most metals have a crystalline structure, meaning that they are made of a highly-organized arrangement of atoms. Metallic glasses are non-crystalline, having a glass-like structure. But unlike common glasses (e.g. window glass) which are typically electrical insulators, metallic glasses have good electrical conductivity. And unlike most crystalline metals, metallic glasses tend to have greater resilience and less stiffness. In some cases, they can be molded like glass into structures stronger than steel.
Of course, these properties – which could have endless engineering uses – all depend on the metals used to form the alloy. Unfortunately, materials science has struggled to fully understand the structural properties of metallic glasses, precisely because it is much more difficult to characterize the structure (and its potential for defects) of an amorphous (non-ordered) material than it is of a crystalline (ordered) material.
However, scientists from the University of New South Wales (UNSW) in Sydney, Australia have published a method to accurately assess the properties of metallic glass alloys before they are even forged – eliminating the need for trial and error alloy formulations. The method works by predicting certain properties of particular alloys, such as detecting structural defects that might discourage the metal from forming in a glass-like state. So far, the UNSW team has used this model to successfully predict more than 200 new metallic glass alloys using metals such as magnesium and silver over the past few years.
If this method is used to find metallic glass alloys that are cost-effective as well as useful, we could be looking at a new era in engineering and materials science!