High-temperature metallic glasses: Status, needs, and opportunities

Metallic glasses have drawn the attention of researchers due to their high strength, hardness, high corrosion, and wear resistance, and ease of thermoplastic forming compared to their counterpart crystalline alloys. While these characteristics are desirable for materials used in extreme environments that often need high corrosion resistance and mechanical strength at elevated temperatures, metallic glasses have found limited use because they crystallize at lower temperatures than the operational temperatures of these applications. Upon crystallization, these characteristics are lost. In recent years, refractory metallic glasses with higher crystallization temperatures have been synthesized, making them potential candidates for use in extreme environments, such as in space and nuclear applications. This review summarizes recently reported metallic glass systems with crystallization temperatures above 700 degrees C. These systems are discussed in terms of glass forming ability, mechanical properties, and other properties relevant to their use in high temperature applications. This article highlights the challenges in the development and implementation of high-temperature metallic glasses, and discusses the needs and research opportunities that exist for expanding our knowledge of these glasses, including potential routes for improving glass forming ability and mechanical properties.