冰箱压缩机阀片断裂失效分析

Fracture Failure Analysis of Compressor Valve in Refrigerator

压缩机是冰箱的心脏,压缩机阀片的断裂失效可引起制冷系统严重故障。本文利用表面应力分析、金相组织和显微硬度分析、成分分析等方法,以及三维视频光学显微镜、扫描电子显微镜等,研究了阀片断裂的特征和机制。断口和裂纹分析表明,阀片失效是疲劳断裂机制,断口具有明显的疲劳扩展区和多处裂纹源。阀片的材质和组织正常。阀片表面的局部损伤容易引起断裂。塑料垫片和阀片形状设计对断裂失效有重要影响。在上述分析的基础上,提出了质量改进措施并取得了良好效果。

Compressor is the heart of refrigerator and the fracture of the valve in compressor will bring about severe failure of cold-producing system. The characteristics and mechanism of valve fracture are investigated in the paper by means of optical microscopy, scanning electronic microscopy （SEM） ,metalligraphic microscopy, microhardness, surface stress and elemental analysis. The SEM analysis indicates that the valve failure is fatigue fracture, and there exist clear fatigue expansion regions and many crack originals in the fracture. The chemical composition and micro structure of the valve are qualified. The local damage on the valve surface is liable to the fracture, and the shape of the valve and plastic flat gasket have impact on the valve fracture. On the basis of the above analysis, some quality improvement measures are presented, and good result is received.