Effect of Ni on stabilization of the supercooled liquid and devitrification of Cu-Zr-Ti bulk glassy alloys

Cu_57.5Zr₃₀Ti₁₀Ni_2.5 and Cu ₅₅Zr₃₀Ti₁₀Ni₅ bulk glassy alloys exhibit high compressive fracture strength of 2200 and 2100 MPa, respectively, and a large supercooled liquid region. Addition of Ni significantly influences devitrification of Cu-Zr-Ti glassy alloy. Cu_57.5Zr ₃₀Ti₁₀Ni_2.5 glassy alloy primarily forms an intermediate intermetallic compound on heating prior to equilibrium by the diffusion-controlled growth with low energy barrier for nucleation whereas Cu₅₅Zr₃₀Ti₁₀Ni₅ and Cu _52.5Zr₃₀Ti₁₀Ni_7.5 glassy alloys devitrify forming equilibrium Aba2 (Cu,Ni)₁₀(Zr,Ti)₇ phase with slightly reduced lattice parameters compared to Cu ₁₀Zr₇ and a small fraction of an unidentified phase. However, pre-existing nanoscale phase of less than 10 nm in size is located in the spaces between the (Cu,Ni)₁₀(Zr,Ti)₇ dendritic phase in the spaces between nanoparticles.