Upcycling Titanium-Based Bulk Metallic Glass Scrap Feedstock Through Compositional Steering

Abstract

Bulk metallic glasses (BMGs) are an emerging commercial material with applications in consumer electronics, fasteners, watches, and precision gears, among other uses. Mass-production of hardware using BMGs requires the production of feedstock material using conventional foundry techniques, normally comprising rods, thin sheets, and powder. Due to the unique amorphous nature and highly designed compositions of BMGs, recycling and upcycling waste products are challenging because the properties of BMGs are highly dependent on their chemical composition and impurity content. In this work, an off-composition, scrap titanium-based BMG feedstock material is upcycled into usable material through the novel use of a correction ingot to steer the composition into either a better glass-forming alloy or an alloy that exhibits improved mechanical performance. In one example, the feedstock, initially with exceptionally poor mechanical properties and low glass-forming-ability, can be compositionally steered into a 3.5 mm thick BMG by mixing it with as little as 25% by mass of a designed alloy.