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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。
A car engine during the bench test, the cast aluminum alloy cylinder block leakage crack through the cracking of the scanning electron microscope fracture observation and metallographic examination and analysis, found that the cylinder body melt purification is not good, there is intensive internal Oxide inclusions and inclusions, and lead to hydrogen absorption of liquid aluminum, resulting in the formation of holes in the aluminum alloy castings. These defects severely weaken the mechanical properties of aluminum alloy castings, as the cradle of microcracks, the maximum stress along the direction of the gradual expansion of the development, leading to oil spill failure. On the basis of the analysis, some improvement measures are put forward.