Bulk Metallic Glasses and Precious Metals: Progress on the Issues
Bulk Metallic glasses are a relatively novel class of materials. They exhibit hardness at least twice as high as conventional alloys, high elasticity, lower casting temperatures, minimal shrinkage on casting and thermoplastic formability. In short, more wear-resistant jewellery can be cast in near-net-shape or processed like plastics. Gold-, platinum- and palladium-based bulk metallic glasses are of significant interest for jewellery. However, several alloys undergo abnormally fast tarnishing, and the conditions for forming a metallic glass often conflict with hallmarking requirements. Progress on these issues is discussed, and an outlook on the future of these materials for jewellery is presented.