期刊论文

Effects of vibratory stress relief on stress relaxation of 7075 Al alloy thin-walled components

中文

振动与冲击

1000-3835

2019

38

1

265-270

10.13465/j.cnki.jvs.2019.01.038

国家自然科学基金(51475483) 湖南省重点研发计划项目(2018NK2065) 湖南省高校科技创新团队支持计划项目(2014207).

本校为第一机构

对铝合金薄壁构件进行振动时效(VSR)实验研究,观察时效对材料表面的影响。通过X-ray表面应力测试、硬度测试和TEM电镜实验,对材料表面特性中的应力分布、相区状况、位错和显微硬度进行了分析,实验结果表明: VSR可使构件加工表面微屈服而造成应力松弛,在30 min、60 min的时效时间里,表面应力幅度分别下降了22%和32%。同时,发现相区内晶粒得到细化,且不同状态下晶界处的位错密度也明显不同,这说明振动交变应力造成了构件表面材料的微观形变,进而阐述了应力松弛的机理和材料显微硬度增长的原因。分析认为VSR对薄壁构件既消减了表面应力峰值,又强化了表面硬度,这对提高材料表面的抗变形能力有利。

The vibration stress relief (VSR) tests were conducted for 7075 Al alloy thin-walled components to observe VSR effects on material surface. Through surface stress measuring with X-ray diffraction (XRD), hardness tests and TEM ones, material surface features including stress distribution, phase domain state, dislocation and micro-hardness were analyzed. The test results showed that VSR can make component machined surface micro-yield and have stress relaxation, the surface stress amplitude decreases 22% and 32%, respectively in 30 min and 60 min;...