Multi-Component Microalloying as a Strategy to Mitigate Relaxation-Induced Embrittlement in Metallic Glasses

The embrittlement of metallic glasses (MGs) due to structural relaxation is a concern for their practical use. Single- or dual-element microalloying have been explored as effective strategies to improve the mechanical and functional properties in MGs. This work considers how multi-component microalloying affects the properties of as-cast and thermally-annealed states. It is found that multi-component microalloying can mitigate relaxation-induced embrittlement and improve the plasticity in annealed states. Changes in glassy states are explored using XRD and DSC, and the mechanical properties in different states are characterized by mechanical testing, microindentation, and nanoindentation. HR-TEM suggests the improvements are due to structural features of the glassy state. The microalloyed relaxed states are more plastic due to a larger number of shear events with lower propagation velocities. It is proposed that multicomponent microalloying is translatable to other systems, and an effective method to achieve properties critical for the adoption of MGs in industry.