摘要
通过对A356-T6铝合金的原位拉伸试验,采用扫描电子显微镜对其进行观察,得出了关于铝合金在应变阶段发生裂纹机制。通过对微结构的定量分析以及裂纹机制的原位研究,描述Si微粒及其共晶分布。原位测试表明,在应变量的增加过程中,由于开裂形成并伴随有Si颗粒的脆性断裂,邻近的微裂纹得以产生。随后,Si的微裂纹引起了枝晶边界上微裂纹的形核。最终裂纹沿枝晶边界进行增长,直到出现不稳定状况。
The cracks propagation mechanism of aluminum alloy during strain stage was investigated by SEM in - situ tension test for A.356 - T6 aluminum alloy. Through quantitative analyses of the microstructure and in - situ study of cracks propagation mechanism, Si particles and their eutectic distribution were described. The result showed that nearby damage occurred with brittle fracture of the Si particles due to cracks formation during increasing strain, the Si micro cracks caused micro cracks nucleation at the dendrite boundary, and the cracks grew along the dendrite boundary until it had the unstable situa- tion.
出处
《轻金属》
CSCD
北大核心
2013年第6期57-59,64,共4页
Light Metals
