不同预变形量T8态时效2195铝锂合金微观组织与强度贡献  

Microstructure and Strength Contribution of T8-aged 2195 Al-Li Alloy With Different Pre-stretching

作　　者：向正武 李劲风[1] 宁红 陈永来[2] 张绪虎[2] XIANG Zhengwu;LI Jinfeng;NING Hong;CHEN Yonglai;ZHANG Xuhu(School of Materials Science and Engineering,Central South University,Changsha 410083;Aerospace Research Institute of Materials&Processing Technology,Beijing 100076)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]航天材料及工艺研究所,北京100076

出　　处：《宇航材料工艺》2021年第4期140-146,共7页Aerospace Materials & Technology

基　　金：863项目(No.2013AA032401)。

摘　　要：以21 mm厚度2195铝锂合金板材为对象,研究了T8态时效时预变形量对其微观组织及力学性能的影响以及不同因素对屈服强度的贡献。结果表明:随着预变形量增大,时效时析出的T1相尺寸减小,数密度增大;而θ'相尺寸和数密度都减小。148℃/38 h时效时,预变形量从3%增加到15%,屈服强度由596 MPa增大到638 MPa,但伸长率由13.8%降低到10.7%。随着预拉伸量逐渐增大,时效析出相对屈服强度贡献逐渐降低,而加工硬化对屈服强度的贡献逐渐提高。合金的屈服强度取决于加工硬化和时效析出强化的共同作用。The effect of pre-stretching on microstructure,mechanical properties and strength contribution of 2195-T8 Al-Li alloy with 21 mm plate thickness was investigated.The results show that,the diameter of T1 precipitates decrease and their number density increase with increasing the pre-stretching;while the diameter and the number density ofθ'precipitates decrease.The yield strength increases from 596 MPa to 638 MPa with increasing pre-stretch from 3%to 15%,but the elongation decreases from 13.8%to 10.7%when aged at 148℃for 38 h.With increasing the pre-stretch,the contribution of precipitation strengthening to yield decreases,and the contribution of work hardening increases.The yield strength depends on the combined effect of work hardening and precipitation strengthening.

关 键 词：铝锂合金 预变形 力学性能 析出相 加工硬化 

分 类 号：TG146.2[一般工业技术—材料科学与工程]