γ相对磁形状记忆合金Co-Ni-Ga马氏体相变和形状记忆效应的影响

Influence of γ Phase on the Martensitic Transformation and Shape Memory Effect of Co-Ni-Ga Ferromagnetic Shape Memory Alloy

摘要:

利用扫描电镜、X射线衍射仪、差示扫描量热分析仪和材料试验机等手段，研究不同热处理条件下γ相对Co44Ni26Ga30合金马氏体相变温度、力学性能和形状记忆效应的影响。结果表明：随热处理保温时间的延长，γ相析出增多，使得马氏体相变温度降低；γ相的引入显著改善合金的韧性，但损害了合金的形状记忆回复性能；通过适当的热机械训练可以大幅提高合金的形状记忆回复能力，最大形状回复率可达93%。

Abstract:

By means of SEM, XRD, DSC and a materials testing machine, the effects of γ phase on the martensitic transformation temperature Ms, mechanical properties and shape memory effect of Co44Ni26Ga30 alloy with different heat-treatments were investigated. Results show that the volume fraction of γ phase increased with prolonging the holding time during the heat treatment, giving rise to the decrease of Ms. The introduction of γ phase improved the ductility of the alloy greatly while deteriorated the shape memory recovery ratio. Upon appropriate thermo-mechanical training, the shape recovery ratio can be enhanced significantly to 93%.