等径角挤压(ECAP)技术在NiTi基形状记忆合金中的研究进展  

Development of Equal Channel Angular Pressing in NiTi-Based Shape Memory Alloy

作　　者：张永皞[1] 范啟超[1] 孙明艳[1] 杨琴 陈捷 黄姝珂[1] Zhang Yonghao;Fan Qichao;Sun Mingyan;Yang Qin;Chen Jie;Huang Shuke(Institute of Machinery Manufacturing Technology,China Academy of Engineering Physics,Mianyang 621999,China)

机构地区：[1]中国工程物理研究院机械制造工艺研究所,四川绵阳621999

出　　处：《稀有金属》2023年第9期1263-1273,共11页Chinese Journal of Rare Metals

基　　金：国家自然科学基金NSAF联合基金项目(U1930207);国家自然科学基金青年基金项目(51901214)资助。

摘　　要：NiTi基形状记忆合金具有优异的形状记忆性能和超弹性,同时还具有强度高、抗疲劳性能优良、抗腐蚀性能好等一系列优点,已在航空航天、核电以及军工等领域取得了应用,是目前各类主流形状记忆合金中最具有实际工程应用价值的合金种类。为了提高NiTi基形状记忆合金的综合性能,人们通过各种手段开展了大量研究工作,渐渐深入认识了NiTi基合金的微观组织与相组成,以及合金相变行为、形状回复能力和力学性能等的主要影响因素,并一直尝试对合金的性能进行进一步提升。等径角挤压(ECAP)技术是目前最具有工业化应用前景的大塑性变形方法之一,该技术近年来在NiTi基形状记忆合金的研究中得到了越来越多的采用。根据目前的报道,ECAP通过显著细化合金微观组织,不仅能够实现力学性能的提高,同时还能对合金的相变行为、形状回复性能、耐磨性能等一系列性能产生有益的影响。基于此,本文整理了近年来国内外ECAP技术在NiTi基形状记忆合金中的研究成果,总结了NiTi基合金常用的ECAP参数以及该技术对合金微观组织、力学性能、相变行为以及记忆性能等各个方面的影响,分析了其优势以及目前主要存在的不足,并对日后的改进和优化方向进行了展望。With excellent shape memory effect,superelasticity and many other properties,NiTi based alloys have been widely used in fields such as aviation/aerospace,nuclear power and military industry.For engineering applications,NiTi based alloys are also one of the most important sorts from main shape memory alloys.Many research works have been conducted to improve the comprehensive performance of NiTi based shape memory alloys.With those works,microstructures,constituent phases,phase transformation behavior,shape memory ability and mechanical property of the alloys have been recognized progressively.Moreover,further efforts are also continuously carried out to improve the properties of NiTi based alloys.Equal channel angular pressing(ECAP)is one kind of severe plastic deformation(SPD)process which can produce three-dimensional bulk materials with fine grains very efficient.ECAP is one of the best ways for industrial application among different SPD methods.This technique has been applied with many metallic materials and now people try to use it within the field from traditional structural materials to functional materials.Therefore,more and more works have been reported with ECAPed NiTi based shape memory alloys,including NiTi dual alloys and several NiTi based ternary alloys.From the investigations we can draw the conclusion that ECAP can not only increase the mechanical property,but also increase many other properties such as shape memory effect and wear resistance ability,of the NiTi based alloys.With the existing reports,ECAP is very efficient at grain refinement and usually a grain size of 300~600 nm can be obtained.Compared with normal grain refining methods,ECAP process can obtain ultrafine grains which with high angle grain boundaries,not subgrains which with low angle grain boundaries.Beside grain refining,ECAP can also introduce large number of dislocations.Many works have reported the remarkable strengthening effect which caused by the dense dislocations in different kind of NiTi based alloys.ECAP is not always

关 键 词：等径角挤压(ECAP) NiTi基形状记忆合金 晶粒细化 性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]