飞机刹车盘钢夹断裂分析

Failure Analysis of Brake Plate Clamps of Plane

飞机刹车盘钢夹在使用过程中发生断裂。利用体视显微镜、金相显微镜、扫描电子显微镜、能谱仪等手段对发生断裂的钢夹的断口宏观微观形貌、组织、微区成分和显微硬度进行分析。结果表明:钢夹的断裂模式为疲劳断裂;断裂原因与钢夹材料硬度明显低于设计要求,显微组织中存在大量条状氧化物夹杂(大于3级),导致材料强度降低、承载能力不足有关;建议严格控制钢夹热处理工艺,原材料缺陷以及零件装配公差。

The carbon/carbon brake plate clamp of a plane fractured during service. Fracture morphology, microstructure, micro-area composition and micro-hardness were analyzed by means of stereo microscopy, metallographic microscopy, scanning electron microscopy and energy dispersive spectroscopy. The analysis results indicate that the failure mode is fatigue fracture, which is related to the insufficient bearing capacity, resulting from the significantly lower material hardness and lots of band-like oxide inclusions in the microstructure. It is recommended that the material heat treatment process, raw material defects and partassembling tolerance should be strictly controlled.