(北京航空制造工程研究所,北京 100024)
摘 要: 某型d 6 mm×1.5 mm航空用Ti6Al4V钛合金沉头螺栓在测试抗拉强度时出现了螺栓头部与光杆脱离的失效情况。通过对失效零件的宏微观断口、金相组织及化学成分分析,找出失效原因并改进工艺方案。结果表明:这种失效现象起因于螺栓头部端面的微裂纹,通过调整原材料截断装置,螺栓头部的微裂纹可以明显缩短或消除。
关键字: 钛合金;螺栓;拉伸断裂;失效分析;断口分析
(Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024, China)
Abstract:The failure of head and rod separation appears in a type of d 6 mm×1.5 mm aircraft Ti6Al4V titanium alloy countersunk head bolt in tensile strength test. The failed part was investigated by macro and micro fracture analysis, and the microstructure and chemical composition were analysed to find out the reason and improve the process scheme. The results show that micro cracks on the head of the bolt face are the proximate failure cause. By adjusting the raw material cutting device, micro crack on bolt head can be significantly reduced or eliminated.
Key words: titanium alloy; bolt; stretched fracture; failure analysis; fracture analysis