关键词: 飞行器仪表、设备, 电连接器, 热循环, 加速试验, 失效分析

Abstract: The rapid development of space technology has put forward higher requirements for electrical connector reliability. The reliability issues of electrical connectors under thermal cycling conditions are presented. A thermal cycling test scheme combined with the accelerated life test theory is proposed for electrical connectors. The accelerated thermal cycling test is carried out. It is found that the value of contact resistance increases slowly with the number of thermal cycles. The extrapolated value of thermal cycling life is calculated by gray model. Finally, the failure analysis on the jack of typical samples is illustrated. It is indicated that the crystal size rises, the fragmentation degree of the sub structure and the dislocation density increase, and there is more β′phase appearing in the jack of samples after test. The result shows that the change of microstructure is the fundamental reason for the stress relaxation phenomenon of jacks and the contact reliability degradation of electrical connectors.

Key words: instrument and equipment of aerocraft, electrical connector, thermal cycling, accelerated life test, failure analysis