Preparation of Ti₅₀Ni₃₀Cu₁₀Pd₁₀ shape memory alloys by rapid solidification

Equiatomic TiNi based alloys have attracted much attention due to their shape memory effect,superelasticity and damping capacity. Previous in vestigations have proved that the replacement of nickel with copper and palladium is an effective way to improve their property. In the last decades, the ternary Ti-Ni-Cu and Ti-Ni-Pd shape memory alloys (SMAs) have been studied intensively. But the investigations of Ti-Ni-Cu-Pd quaternary alloys are scarce. In this paper, Ti₅₀Ni₃₀Cu₁₀Pd₁₀ alloys were preparted by using melt-spinning method. The effect of rapid solidification on the lattice structure, transformation temperature and microstructure was investigated. It is found that the lattice constant of parent phase (cubic B2) increases with the wheel speed. The martensite phase (orthorhombic B19) exists in the as-spun ribbons when the wheel speed is up to V= 50 m/s. DSC analysis reveals that the martensitic transformation temperatures are 285,290 and 300 K for the alloys solidified at V = 10,30 and 50 m/s, respectively. Ti₅₀Ni₃₀Cu₁₀Pd₁₀ alloys possess good shape memory effect around room temperature.