Preparation of single crystal CuAlNiBe SMA and its performances

A novel quaternary CuAlNiBe shape memory alloy (SMA) Cu-11.5Al-3.8Ni-0.4Be (wt%) was designed and synthesized in this study. The single crystal of this alloy was fabricated by means of a high temperature gradient directional solidification furnace with a selective growing crystallizer. After solid solution treatment, the phase transformation points (including Ms, Mf, As and Af) were determined by DSC; the bending shape memory performance, the maximal recoverable deformations, the tensile strength and the elongation percentage were measured. Its maximum recoverable strain reached 10% which approximately equals to or exceeds the reported maximum recoverable strain for polycrystalline TiNi alloy. The number of bend-relaxing times arrived at 750. Both results implied that this single crystal alloy may become a promising candidate to challenge TiNi SMA.