摘要
采用拉伸性能测试及透射电镜(TEM)分析手段研究了1460铝锂合金薄板在145和175℃时效时的力学性能和微观组织的演化。研究结果表明:相比于145℃时效,1460铝锂合金175℃时效响应速率明显加快。在120 h时效时间范围内,175℃时效时合金的延伸率、最高抗拉强度以及屈服强度与抗拉强度差均低于145℃时效时,特别是175℃近峰时效时合金屈服强度与抗拉强度差明显降低。1460铝锂合金145,175℃两个温度时效时的主要脱溶产物均为δ'相(Al_3Li),合金时效初期均快速析出均匀弥散分布的δ'相;175℃时效时δ'相的粗化速度明显高于145℃时效,导致其尺寸随时效时间延长显著粗化,密度明显降低。145℃时效时随时效时间延长,合金在析出δ'相后形成大量的G.P.区;时效后期G.P.区长大,没有T1相(Al_2CuLi)的析出。175℃时效过程中合金在析出δ'相后快速析出T1相;时效后期T1相数量明显减少而尺寸显著粗化。
The mechanical properties and microstiuctural evolution of 1460 Al-Li alloy sheet aged at 145 and 175 ℃ were studied by tensile test machine and transmission electronic microscopy （ TEM ）. The results showed that the aging response rate of the alloy aged at 175 ℃ increased significantly compared to 145 ℃. The elongation, maximum tensile strength and difference between the yield strength and tensile strength of the alloy aged at 175 ℃ were lower than that of the alloy aged at 145 ℃ within 120 h aging time. The main strengthening products were δ＇（AIzLi） phases both at 145 and 175 ℃. During early aging, the alloys both precipitated uniformly dispersed δ＇ phase. The δ＇ phase of alloy aged at 175 % had a higher coarsening rate than the alloy aged at 145 ℃ , which resulted in the size increase and the density decrease of δ＇ phase with the aging time extension. After 8＇ phase appearing at 145 ℃ , the alloy formed a large number of G.P. Zones which grew up during over aged stage without precipitating Tl （Al2CuLi） phase; whereas the alloy aged at 175 ℃ precipitated Tl phase rapidly after forming of δ＇ phase, then the number of Tl phase redueed and the size coarsened significantly during over aged stage.
作者
林小红
李劲风
陈永来
张绪虎
许秀芝
郑子樵
Lin Xiaohong;Li Jinfeng;Chen Yonglai;Zhang Xuhu;Xu Xiuzhi;Zheng Ziqiao(School of Materials Science and Engineering, Central South University, Changsha 410083, China;Aerospace Research Institute of Materials and Processing Technology, Beijing 100076, China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2017年第12期1293-1298,共6页
Chinese Journal of Rare Metals
基金
国家科技部863项目(2013AA032401)资助
关键词
铝锂合金
力学性能
微观组织
Al-Li alloy
mechanical property
microstructure
