铸造铝合金汽缸体开裂分析  

Crack Analysis on Aluminum Alloy Engine Block Castings

作　　者：程里[1] 

机构地区：[1]重庆理工大学材料科学与工程学院,重庆400057

出　　处：《铸造技术》2011年第12期1694-1697,共4页Foundry Technology

摘　　要：某汽车发动机在进行台架试验时,其铸铝合金的汽缸体出现漏油开裂,通过对开裂部位进行扫描电镜断口观察及金相检验分析,发现汽缸体熔体净化不好,内部存在密集的氧化物夹渣和夹杂物,并导致铝液吸氢,造成铝合金铸件中孔洞的形成。这些缺陷严重削弱铝合金铸件的力学性能,作为显微裂纹的发源地,使用时沿应力最大方向逐渐扩大发展,导致漏油失效。在分析基础上提出了改进措施。Cracking appeared in engine block while auto car engine was rig-testing examined. The cracking reason was analyzed by observing fracture with SEM and inspecting microstructure. The results show that the oxide inclusions formed in the process of aluminum melting and pouring are the main inclusions in liquid aluminum, which have an important influence on hydrogen absorbed of aluminum liquid, which causes the formation of porosities in the castings. They also weaken the mechanical properties of aluminum alloy castings and is the origin of cracks. The improved measures were also brought forward on the basis of analysis.

关 键 词：铸造铝合金 汽缸体 渣孔 微裂纹 过滤 

分 类 号：TG292[金属学及工艺—铸造] TG245