【摘要】 研究了形变对Ni-Mn-Ga合金马氏体相变及其组织形态的影响,并应用马氏体相变热力学和动力学探讨了适当塑性变形后马氏体相变滞后得以大幅度提高的微观本质。结果表明,随着应变量的增加,马氏体相变温度几乎保持不变,而其逆相变温度则迅速升高,塑性应变导致储存在界面处的弹性应变能的释放是塑性变形提高合金相变滞后的主导因素。更多还原

【Abstract】 Using DSC, TEM and compress test, the effect of deformation on martensitic transformation and microstructure of the Ni-Mn-Ga alloy has been investigated. The mechanism of increase of martensitic transformation hysteresis after optimum plastic deformation has been discussed by thermodynamics and kinetics of martensitic transformation. The results show that the martensitic transformation temperatures keep constant, but reverse transformation temperatures sharply increase with an increase of the pre-deformation strain. The increase of transformation hysteresis in the alloy is mainly due to the release of the elastic energy deposited at the boundary induced by the plastic deformation.更多还原