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 Zr₆₀Al₁₅Ni_25-x TM _x (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. Zr₆₀Al₁₅Ni₁₅Cu ₁₀ 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. Zr ₆₀Al₁₅Ni₂₀Cu₅ 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.