摘要
研究了室温大气环境下不同应力比R和不同应力集中系数Kt条件下2E12高强铝合金的高周疲劳性能,并利用扫描电镜及透射电镜对合金疲劳断口附近的微观组织及疲劳断口进行了分析。研究结果表明,在同一应力水平下,2E12高强铝合金的疲劳寿命随着应力比R的增大而提高;Kt=1时合金的疲劳寿命远远大于Kt=3时合金的疲劳寿命,表明此合金具有明显的缺口效应。疲劳断口由疲劳源区、裂纹扩展区及瞬断区组成。第二相对疲劳裂纹的萌生起着重要的作用,并且初步讨论了有关的疲劳断裂机理。
High cycle fatigue of 2E12 aluminum alloy was investigated under different stress ratio and stress concentration factor at room temperature, and fracture mechanism was discussed. The microstructures and fatigue fracture surfaces of the alloy were examined by transmission electron microscopy and scanning electron microscopy. The results showed that the fatigue life of 2E12 aluminum alloy improves with increasing of stress ratio and the fatigue life of Kt= 1 was longer than that of Kt= 3, exhibiting notch sensitivity. The fatigue fracture consisted of fatigue crack source, fatigue crack growth area and instantaneously fracture area. The second phase particles conduced to crack initiation.
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2009年第1期96-100,共5页
Journal of Aeronautical Materials
基金
国家重点基础研究发展计划973计划(2005CB623705)
关键词
铝合金疲劳寿命
裂纹萌生
断口分析
断裂机理
aluminum allay fatigue life
crack initiation
fracture micrography analysis
fracture mechanism
