Effect of Annealing Temperature on the Shape Memory Properties of Cold-Rolled Dual-Phase Ni-Mn-Ga-Gd Alloy

摘要

The influence of annealing temperature on the shape memory effect(SME) and recovery ratio of cold-rolled dual-phase Ni_(58)Mn_(25)Ga_(16.9)Gd_(0.1) high-temperature shape memory alloy were investigated.The results showed that the SME can be improved by appropriate annealing.SME of 6.0%and recovery ratio of 98%were observed in the rolled alloy at 550 ℃ annealing,which were larger than that of the samples annealed at other temperatures.The annealing temperature was in between the recrystallization temperatures of the martensite and γ phase,which leads to the work-hardening state ofγ phase kept unchanged during annealing process,and therefore,the critical slip stress of γ phase increased.Thus,the plastic deformation of γ phase reduced during the compression process,and the SME increased.