High-Temperature Mo-Based Bulk Metallic Glasses

Among bulk metallic glass (BMG) alloys, molybdenum-based BMGs are lacking due to the weak glass forming ability (GFA) of existing Mo-based alloys. In this talk, I will introduce a novel family of low-cost refractory Mo-Co-B BMGs with enhanced GFA and high thermal stability. These Mo-based BMGs exhibit ultra-high glass transition temperatures up to ~1050 K, paired with exceptional nano-hardness and Young's modulus up to 17.1 GPa and 260 GPa, respectively. The excellent thermal stability and mechanical properties are closely related to the prominent covalent metal-metalloid bonds in the Mo-Co-B BMGs. I will discuss the physical origin of the superior GFA underlying these Mo-based BMGs and the broad implications of our work for the development of other refractory BMGs. Our finding expands the palette of BMG alloys and opens a new arena for the exploration of low-cost refractory BMGs for applications at high temperatures and extreme environments.