锌铝合金阀片断裂失效分析

Fracture Failure Analysis of Zinc-Aluminum Alloy Valve Piece

采用X射线衍射仪、扫描电子显微镜及能谱仪等研究了合金元素对铝锌合金组织的影响。结果表明,锌铝合金中含有Si、Cu、Fe等元素与Al或者Zn易生成金属间化合物。锌铝合金呈现枝状晶形貌,合金中存在大量不规则熔池组织。合金中的杂质元素及氧化物均存在于熔池组织中,这些熔池组织在高倍观察下可见为分散性的微孔。在受到外力时,这些缩孔将成为应力集中点,大量微小缩孔是合金在外力下发生断裂的主要原因。

The effect of alloy elements on the microstructure of Al-Zn alloy was investigated by using X-ray diffractometer, scanning electron microscope（SEM） and energy spectrometer. The results show that the elements such as Si,Cu, Fe are easy to produce intermetallic compounds with Al or Zn in Al-Zn alloy. Al-Zn alloy exhibits dendritic morphology and a large number of irregular molten pool structure exists in the alloy. The impurity elements and oxides in the alloy are existed in the molten pool, which are visible dispersed micro-perforations under high times observation. When the alloy is subjected to external force, these shrinkage becomes the stress concentration point, and a large number of tiny shrinkage is the main reason for the fracture of the alloy under external force.