The Analysis And Research On Fretting Agglomeration To The Electrical Contact Reliability

With numbers of experimental researches and enormous amount of statistical data, it can be found that when pollutants agglomerate on the contact surface, the contact resistance will dramatically increase, even open circuit, causing electrical contact failure.In this paper, I integrate electrical contact's method of research fretting with tribological mechanical's method of research fretting, I set up a fretting agglomeration kinematics model, get two processes of fretting agglomeration: pollutants accumulated at both ends of the fretting region,pollutants agglomerate to the fretting region center. Through the calculation of agglomeration formation process, I obtain the critical height and critical volume of agglomeration formation. Through the discussion of critical height and critical volume, I come to conclusion of agglomeration formation condition, which is greater actual height than the critical height. Through the discussion of the agglomeration formation conditions, come together to form the influencing factors: high critical,small critical volume and great growth velocity of agglomeration which all will be conductive to the occurrence of aggregation.At the same time, I preliminary discuss rough surface morphology of three-dimensional characteristics to the fretting agglomeration influence, I obtain conclusion: for different types of friction surface, the trough size is dangerous to exist to increase of possibility of particles depression, which is favorable for the agglomeration, and possibility of agglomeration greatly increase.