铝合金铸件螺丝孔开裂原因分析

Fracture analysis of the screw hole on aluminum alloy casting

通过宏观检验、化学成分分析、金相组织检验以及电镜微观观察等方法对铝合金铸件螺丝孔开裂原因进行分析。结果表明,由于铝合金铸件在铸造加工过程中,由于铸造工艺不当,形成冷隔夹杂和少量气孔,在后期装配过程中受外力作用,从而在螺丝孔应力集中处引起铝合金铸件的脆性开裂。

The cracking of the screw hole on aluminum alloy casting was investigated by macroexamination, chemical component analysis, metallography inspection and electron microscope analysis. The results showed that the foundry ingot technique of aluminum alloy casting was improper during casting process. The cold insulation inclusions and a little porosity were formed. In the later assembling process,stress concentration in the screw hole was existed under external force action. It caused that brittle crack of aluminum alloy casting took place.