某航空发动机在启动试验时其滑油泵的分油盘发生断裂, 对分油盘断口进行了宏观和微观观察, 并对显微组织进行了分析, 以找出分油盘断裂的原因。结果表明: 分油盘中心孔位置断口呈熔融后凝固的特征, 其断裂性质为过载断裂; 因分油盘中心孔位置摩擦严重产生高温, 使晶粒长大、晶界弱化, 甚至熔化并沿着载荷方向的晶界开裂, 从而导致分油盘发生断裂。

The oil-separating pan of an engine failed during starting testing. In order to find out the failure cause, macro and micro observation on the fracture surface and microstructure examination were carried out. The results show that the fracture surface presented solidification feature after melting, and the fracture mode was overload fracture. The high temperature, which caused serious friction nearby center hole of oil-separating pan, led to grain growing up, grain boundary weakness, melting and cracking in loading direction.