Acta Metallurgica Sinica (English Letters) ›› 2015, Vol. 28 ›› Issue (11): 1403-1406.DOI: 10.1007/s40195-015-0339-0

• Orginal Article • Previous Articles     Next Articles

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

Xin Zhang1(), Qing-Suo Liu1(), Xian-Shun Zeng1, Jie-He Sui2, Wei Cai2, Ai-Lian Liu3   

  1. 1 School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
    2 National Key Laboratory Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China
    3 College of Material Science and Engineering, Heilongjiang University of Science and Technology, Harbin 150022, China
  • Received:2015-07-28 Revised:2015-10-27 Online:2015-11-17 Published:2015-11-20

Abstract:

The influence of annealing temperature on the shape memory effect (SME) and recovery ratio of cold-rolled dual-phase Ni58Mn25Ga16.9Gd0.1 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 °C 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 of γ 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.

Key words: Shape memory alloys, Recrystallization, Cold rolling, Ni-Mn-Ga