Low expansion in [(Fe0.9Co0.1)0.72B0.24Nb0.04]95.5Y4.5 bulk metallic glass

The thermal expansion behavior of an iron-based bulk metallic glass (BMG) [(Fe0.9Co0.1)0.72B0.24Nb0.04]95.5Y4.5 is studied. The expansion coefficient in the wide temperature range of 100–300 K keeps in a constant, which is close to that of the Kovar alloy. Furthermore, the expansion coefficient of the BMG can be tuned by annealing below glass transition temperature. The results have implication for understanding the origin of low expansion, and the BMG may have a potential for commercial low expansion material.