Shape-memory effect in Co-Ni single crystal①
(1. State Key Laboratory of Metal Matrix Composites,
Shanghai Jiaotong University, Shanghai 200030, China;
2. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China)
Shanghai Jiaotong University, Shanghai 200030, China;
2. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China)
Abstract: The thermal shape-memory effect at room temperature for Co-32%Ni(mass fraction) magnetic shape memory alloy of single crystal was presented. When compressing the sample along the [001] direction at room temperature, strain can be recovered to some extent during later heating and the recovery rate varies with the pre-strain. But no obvious recoverable strain can be obtained along other crystal directions. For the thermal-mechanical training of the sample along
[001], the recovery strain decreases obviously during the second round of compress and nearly no recovery happens after the third round of compress. A possible mechanism based on reversible motions of Shockley partial dislocations was proposed.
[001], the recovery strain decreases obviously during the second round of compress and nearly no recovery happens after the third round of compress. A possible mechanism based on reversible motions of Shockley partial dislocations was proposed.
Key words: Co-based alloys; shape memory effect; Shockley partial dislocation