Data-driven discovery of a universal indicator for metallic glass forming ability.

Despite the importance of glass forming ability as a major alloy characteristic, it is poorly understood and its quantification has been experimentally laborious and computationally challenging. Here, we uncover that the glass forming ability of an alloy is represented in its amorphous structure far away from equilibrium, which can be exposed by conventional X-ray diffraction. Specifically, we fabricated roughly 5,700 alloys from 12 alloy systems and characterized the full-width at half-maximum, Δq, of the first diffraction peak in the X-ray diffraction pattern. A strong correlation between high glass forming ability and a large Δq was found. This correlation indicates that a large dispersion of structural units comprising the amorphous structure is the universal indicator for high metallic glass formation. When paired with combinatorial synthesis, the correlation enhances throughput by up to 100 times compared to today's state-of-the-art combinatorial methods and will facilitate the discovery of bulk metallic glasses.

Fast Screening of Corrosion Trends in Metallic Glasses.

Corrosion trends in the bulk metallic glass forming alloy system Zr-Cu-Al are studied through a fast screening visual characterization method of thin film alloy libraries prepared by magnetron co-sputtering. Significant distinct brightness changes are present within the Zr-Cu-Al system when the thin film library is immersed in 3.5 wt % NaCl. Through additional quantification of corrosion current density, a correlation between change in brightness and corrosion current density is revealed, suggesting an effective rapid screening of corrosion simply by a visual method. For materials discovery with optimized multiproperties, we utilize the corrosion fast screening results and superimpose them on the composition dependence of the glass forming ability. This allows us to rapidly identify alloys with the best combination of glass forming ability and corrosion resistance, which we then confirm in bulk form.