摘要
研究室温大气环境下2E12铝合金微观组织与疲劳裂纹扩展行为之间的关系,并分别利用光学显微镜、透射电镜和扫描电镜对合金的微观组织及疲劳断口进行分析。结果表明:合金的疲劳裂纹扩展速率与合金中微米级第二相粒子的体积分数成正比,且随着亚微米级第二相粒子尺寸的增加及晶粒尺寸的减小,合金的疲劳裂纹扩展速率明显降低,尤其是在Pairs区及以后,其值降低30%;在低速扩展区,合金断口呈现脆性的准解理断裂特征,在中速扩展区,合金出现清晰的疲劳条纹。
The interrelationship between microstructure and fatigue crack propagation behaviors of 2E12 aluminum alloys was investigated at room temperature in air. The microstructures and fatigue fracture surfaces of the alloy were examined by optical microscopy, transmission electron microscopy and scanning electron microscopy. The results show that the fatigue crack growth rate is proportional to the volume fraction of micro-sized second-phase particles. And with the increase of submicro-sized second-phase particles size and the decrease of grain size, the fatigue cracks propagate much slowly, reducing by 30% or more at Pairs region. In a low fatigue crack growth rate region, alloy shows quasi-cleavage fracture features. In a middle fatigue crack growth rate region, the fatigue striation features are clear.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2010年第7期1275-1281,共7页
The Chinese Journal of Nonferrous Metals
基金
国家重点基础研究发展计划资助项目(2005CB623705)
关键词
2E12铝合金
疲劳裂纹扩展
晶粒
微米级第二相
亚微米级第二相
2E12 aluminum alloy
fatigue crack propagation
grain
micro-sized second-phase particles
submicro-sized second-phase particles
