SEM原位观察3104铝合金板材的断裂行为

Rupture behavior of 3104 aluminum alloy sheet in-situ observation by SEM

利用原位拉伸扫描电镜,观察并研究了3104铝合金冷轧板动态拉伸过程中裂纹萌生和裂纹扩展情况,讨论了裂纹萌生和扩展与板材微观组织之间的关系。结果表明:在拉伸过程中,裂纹起源于滑移带处,并沿滑移带扩展。裂纹扩展路径受拉伸应力状态以及板材内部晶粒和粗大第二相分布的影响。原位拉伸断裂模式为韧窝断裂和剪切断裂复合断裂模式,断口形貌受裂纹扩展应力状态的影响。

Crack initiation and propagation in 3104 aluminum alloy cold rolling sheet during dynamic tensile process were investigated by in-situ tensile scanning electron microscope. The relationship between alloy microstructure and crack initiation and propagation was discussed. The results show that cracks during tensile process originate in slip bands,and then propagate along the slip bands. The crack propagation path is influenced by the tensile stress state,the grain structure and the distribution of coarse second phase particles in the cold rolling sheet. The in-situ tensile fracture mode is complex,due to combination of the void-mode fracture and the shear fracture. The fracture morphology is affected by the stress state of the crack growth.