时效工艺对纳米结构2297铝锂合金力学性能与微观组织的影响  

Effect of aging process on mechanical properties and microstructure of nanostructured 2297 aluminum-lithium alloy

作　　者：李婷婷 罗军钱 梁晟 黄天林[1] 吴桂林[1] Li Tingting;Luo Junqian;Liang Sheng;Huang Tianlin;Wu Guilin(International Joint Laboratory for Light Alloys(MOE),College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学材料科学与工程学院轻合金材料国际合作联合实验室(教育部),重庆400044

出　　处：《金属热处理》2020年第3期86-91,共6页Heat Treatment of Metals

基　　金：国家重点研发计划(2016YFB0700403)。

摘　　要：采用535℃×2 h固溶制度,将热锻态2297铝锂合金固溶水淬后冷轧,冷轧压下量为95%,然后将轧制样品在不同温度(120~190℃)和时间(0~80 h)范围内进行时效处理。采用拉伸、扫描电镜(SEM)和透射电镜(TEM)等测试方法,分析时效温度和时间对铝锂合金组织与性能的影响。结果表明:时效前的大塑性变形能获得纳米结构组织,能促进T1相均匀细小地析出,缩短合金达到峰时效的时间,最终成功制备了高强高塑性铝锂合金。在120~140℃温区内时效时,时效温度越高,达到峰时效的时间越短、强度越高。140℃达到峰时效时间缩短为40 h,此时合金的抗拉强度、屈服强度和伸长率分别为525 MPa、478 MPa和7.7%,主要强化相为细小的T1相。在170~190℃温区内时效时,时效温度越高,达到峰时效的时间越短,但抗拉强度与屈服强度迅速下降。170℃时效8 h达到峰时效状态,此时合金的抗拉强度、屈服强度和伸长率分别是503 MPa、462 MPa和5.0%,主要强化相仍为T1相,但已经明显粗化。A hot-forged 2297 aluminum-lithium alloy was solution treated at 535℃for 2 h then water quenched,followed by cold rolling with 95%reduction,and then aged at different temperatures(140-190℃)for different time(0-80 h).The effects of aging temperature and time on the microstructure and properties of the alloy were analyzed by means of tensile testing,scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The results show that the large plastic deformation prior to aging leads to nanostructure in the alloy and promotes homogenous precipitation of fine T1 phase,which greatly shortens the time for the alloy to reach peak aging.Consequently,the aluminum-lithium alloy with high strength and high plasticity is successfully obtained.When aging at temperature in range of 120-140℃,the higher the aging temperature,the shorter the peak aging time and the higher the strength.After peak aging at 140℃for 40 h,the tensile strength,yield strength,and elongation of the alloy are 525 MPa,478 MPa,and 7.7%,respectively,and the main reinforcement phase is fine T1 phase.When aging at temperature in range of 170-190℃,the higher the aging temperature,the shorter the peak aging time,but the tensile strength and yield strength decrease rapidly.After peak aging at 170℃for 8 h,the tensile strength,yield strength,and elongation of the alloy are 503 MPa,462 MPa,and 5.0%,respectively,and the main reinforcement phase is still T1 phase,but it has obviously coarsened.

关 键 词：2297铝锂合金 纳米结构 力学性能 微观组织 时效 

分 类 号：TG113.25[金属学及工艺—物理冶金]