Developments in High Magnesium-Content Bulk Metallic Glasses and Future Possibilities

Abstract

Amorphous alloys or metallic glasses have been earmarked as “the most significant development in materials science since the discovery of plastics over 50 years ago” (Mike Ashby, 2011) and are gaining significant attraction as ‘Next Generation’ materials [1].

When compared to crystalline alloys, amorphous alloys possess superior strengths (approximately three-times that of their crystalline counter-parts), which approach the theoretical strength maximum [1], the highest elastic limits of all metallic materials (at least twice that of regular metals), improved corrosion resistance, and amorphous alloys based on palladium exhibit the highest damage-tolerance of all materials known [1,2]. Unlike crystalline metal alloys, metallic glasses exhibit a glass transition temperature, above which the alloy exists in a ‘super-cooled liquid’ state, where viscosity or flow stress is reduced by several orders of magnitude. Here, superplastic forming techniques (similar to plastics and ceramic glasses) such as forging, extrusion, drawing and blow moulding can be performed [3].