TC4钛合金耳片断裂原因分析

分析了由TC4钛合金材料制造的飞机减速板接头耳片在使用中发生断裂的故障。作动筒通过螺杆与该减速板接头耳片相连接并驱动减速板工作。通过对断裂件进行外观检查,断口宏、微观观察、能谱分析,金相组织检验等手段,确定了减速板接头耳片的断裂性质及失效原因。结果表明:该减速板接头耳片的断裂性质为疲劳断裂,其断裂源是由耳片内孔与连接螺杆之间接触所产生的微动磨损引发的;产生微动磨损的原因是由于耳片与连接作动筒的螺杆之间配合间隙不当和润滑不良所致。

Fracture Analysis of TC4 Titanium Alloy Ear Plate

The connecting auricle of actuating cylinder of aircraft speed brake fractured during service. The fractured part was made of TCA titanium alloy. In order to find out the failure cause, macro and micro observation, microstructure examination and chemical composition analysis were carried out. The results show that the fracture of the auricle is fatigue fracture. There existed fretting wear between the inner wall of the auricle and the connecting bolt, which caused the initiation of fatigue crack. The fretting wear resulted from the improper fitting and lubrication between the auricle and the bolt.