Effects of Cu, Fe and Co addition on the glass-forming ability and mechanical properties of Zr-Al-Ni bulk metallic glasses

The thermal stability, glass-forming ability (GFA) and mechanical properties of Zr60Al15Ni25−xTMx (TM = Cu, Fe and Co, x = 0–10) bulk metallic glasses (BMGs) were systematically investigated. Additional 5–10 at.% Cu greatly enhances the thermal stability and GFA of the base alloy. Zr60Al15Ni15Cu10 BMG exhibits the largest supercooled liquid region of 104 K and critical diameter of 18 mm. However, addition of 5-10 at.% Fe or Co decrease the thermal stability and GFA. In addition, the plasticity of the BMG can be improved by adding of Cu, while the strength is decreased slightly. Zr60Al15Ni20Cu5 BMG has the largest plastic strain of 5.5% with a yield stress of 1755 MPa and Young’s modulus of 83 GPa. Addition of Co brings an increase of strength but a lower of plasticity, and additional Fe reduces the strength and plasticity simultaneously.