Liquidmetal (also known as metallic glass or amorphous metal) is a newly developed and recently commercialized class of material that does not have a crystalline structure. These alloys possess exceptional mechanical properties. In fact, when compared with their crystalline counterparts, their hardness is almost triple and their yield strength nearly quadruple. Their melting point is about 370°C (698°F) for gold and 550°C (1022°F) for platinum, and they have minimal solidification shrinkage (one percent or less) due to the absence of crystallization during solidification. Their unique crystallization behaviors allow them to be processed in the supercooled liquid region (150°–170°C (302°–338°F) for gold and 250°–270°C (482°–518°F) for platinum), where they can actually be processed like thermoplastics. The combination of unusual material properties and cost-effective processing methods these alloys allow opens opportunities for new jewelry designs and processing techniques not possible with crystalline gold and platinum alloys. In this paper, the design, development and properties of these two metallic glass families (based on gold and platinum) are discussed.

Author(s): Boonrat Lohwangwatana, Jan Schroers, William L. Johnson, William L.