The Behavior of Phase Transformation Characteristics and Ageing on Alloying Method of CuZnAl Shape Memory Alloy
The effect of transformation temperature and phase transformation characteristics by alloying method of CuZnAl shape memory alloy with a small of misch metal and Zr contents were investigated. The addition of misch metal and Zr was very effective for reducing the grain size. After solution treatment, the specimens were post-quench aged or step quenched at 373K to 623K for variation of hardness value. It was found that the hardness value was very increased at 473K and 523K. The fracture mode has been changed from trans granular brittle fracture to ductile fracture with void formation and coalescence by the addition of misch metal and Zr. Ageing of the β-phase decreased the Ms temperature, but that of the martensite phase increases the As temperature. The change in As temperature with post-quench aging can be attributed to recovery of order in the β-phase.
Hyungsun Kim, Junichi Hojo and Soo Wohn Lee
G. S. Yang et al., "The Behavior of Phase Transformation Characteristics and Ageing on Alloying Method of CuZnAl Shape Memory Alloy", Materials Science Forum, Vols. 544-545, pp. 487-490, 2007