摘要
本文通过对改进技术研制的Ti-50.0at%Ni单晶形状记忆合金进行力热耦合实验,得到不同温度下的宏观应力应变曲线,探讨了温度对马氏体相变特性的影响规律,分析了此材料的形状记忆性、超弹性能等一系列力学性能,从而对它的力学特性有了更深入全面的了解。由此发现,此TiNi单晶具有非常好的形状记忆性能,其最大可恢复应变高达10.83%,达到理论计算值。而由于强化机制的减弱,其塑性变形屈服强度较低,只呈现部分超弹性。
The mechanic properties in the Ti-50.0at% Ni single crystals were studied, The crystals were prepared by means of improved Bridgeman method of unidirectional solidification technology. Analysis of mechanical-themal coupled experimental curves was performed and the variational discipline of the param- eters were summarized by fitting the curves. The maximum tensile recoverable strain of the single crystal was 10.83 %, which is very close to the theoretical maximum. There was no strengthen phase in the ma- trix of equiatomic TiNi single crystal, thus the plastic deformation yield strength of the alloy is very low and the specimen has slipped before the stress reached the critical stress of stress-induced martensitic transformation. Therefore, above the Af point, only part of the superelasticity was exhibited since irre- versible plastic deformation was introduced.
出处
《力学季刊》
CSCD
北大核心
2012年第3期367-374,共8页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(11072062
11172068)
国家博士点基金(20110071110013)
关键词
形状记忆合金
TINI
单晶
马氏体相变
力热耦合实验
shape memory alloy
TiNi
single crystal
martensitic transformation
mechanical-themalcoupled experiment
