摘要
振动时效是一种能有效降低残余应力的工艺技术,但是工件在振动时效过程中微观组织和宏观力学性能都会发生变化。通过激振器和试验机两种装置研究7075高强铝合金板的振动时效发现,残余应力的松弛也伴随着材料力学性能的下降。断口扫描电镜分析表明,杂质相和第二相粒子造成的组织缺陷是疲劳性能降低的主要原因,但两种情况下略有不同。结果认为振动时效除了应合理选择动应力,激振频率对材料残余应力松弛与力学性能也有重要影响,疲劳累积损伤理论是另一重要影响因素。
Vibratory stress relief （VSR） is an Effective technology in relaxing residual stress, which may also change material microstructure and mechanical properties. VSR of 7075 high - strength aluminum alloy by vibration exciter device and testing machine shows that the relaxation of residual stress cau- ses decreases of mechanical properties. Analysis of the fracture SEM shows that microstructure defeats caused by impurity phase mad second - phase parti- cles are reasons reducing the fatigue performance or mechanical properties, but there are differences in two conditions. The results suggest that exciting frequency and fatigue cumulative damage rule also have great impacts on residual stress relaxation and material mechanical properties except dynamic stress.
出处
《轻金属》
CSCD
北大核心
2011年第2期53-60,共8页
Light Metals
基金
国家重点基础研究发展规划项目973项目(编号:2005CB623708)
关键词
振动时效
残余应力
力学性能
激振频率
疲劳累积损伤
vibratory stress relief
residual stress
mechanical properties
exciting frequency
fatigue cumulative damage
