预变形对铝锂合金蠕变时效行为及微观组织演变的影响  

Effect of pre-deformation on creep aging behavior and microstructural evolution of Al-Li alloy

作　　者：段炼 湛利华 徐永谦[1,2,3] 黄明辉 DUAN Lian;ZHAN Li-hua;XU Yong-qian;HUANG Ming-hui(Light Alloy Research Institute,Central South University,Changsha 410083,China;School of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China;State Key Laboratory of High Performance Complex Manufacturing,Central South University,Changsha 410083,China)

机构地区：[1]中南大学轻合金研究院,湖南长沙410083 [2]中南大学机电工程学院,湖南长沙410083 [3]中南大学高性能复杂制造国家重点试验室,湖南长沙410083

出　　处：《塑性工程学报》2020年第8期106-115,共10页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51675538);国家重点研发计划项目(2017YFB0306300);国家重点基础研究计划项目(2014CB046602);国防基础科研计划重大项目(JCKY2014203A001)。

摘　　要：通过室温拉伸、透射电子显微镜(TEM)等手段研究预变形对2195铝锂合金蠕变时效行为、力学性能和微观组织演变的影响。结果表明:预变形引入后,合金蠕变量有所提升。相比于没有预变形的合金,其蠕变阶段由典型的双阶段蠕变变为具有双初级蠕变阶段的四阶段蠕变。预变形带来的大量位错加速了T1相和θ’相的析出,并对T1相有明显的细化作用,使得合金的析出相强化作用大大加强。因此,时效后的屈服强度和抗拉强度较没有预变形的合金均有明显提升,伸长率降低;同时,预变形的引入加快了时效进程,有利于提高铝锂合金蠕变时效成形成性效率。The effect of pre-deformation on creep aging behavior,mechanical properties and microstructure evolution of 2195 Al-Li alloy was studied by means of tensile test at room temperature and transmission electron microscope( TEM). The results show that the creep amount increases after the introduction of pre-deformation,and compared with the alloy without pre-deformation,the creep stage changes from a typical two-stage creep to a four-stage creep containing a dual-primary creep stage. A large number of dislocations caused by predeformation accelerate the precipitation of T1 and θ’ phase,and have an obvious refining effect on T1 phase,which greatly enhances the precipitation strengthening effect of the alloy. Therefore,the yield strength and tensile strength after aging significantly increase and the elongation decreases compared with the alloys without pre-deformation. At the same time,the introduction of pre-deformation accelerates the aging process,which is beneficial to improve the creep aging forming shape and performance efficiency of Al-Li alloy.

关 键 词：铝锂合金 蠕变时效 时效析出相 预变形 

分 类 号：TG146.2[一般工业技术—材料科学与工程]