A comparative study on the electrical contact behavior of CuZn40 and AgCu10 alloys under fretting wear: Effect of current load

Abstract

The current load is one of the most significant factors in the reliability of electrical contact under fretting conditions. In this paper, the fretting wear experiments are conducted for CuZn40 and AgCu10 alloys with varied current loads. The variations of electrical contact resistance (ECR), ECR endurance, temperature, and wear volume with the increasing current load of two alloy materials under fretting conditions are investigated, and the differences between their electrical contact behaviors are compared. The microstructures of the surface wear morphology are examined to reveal the mechanisms of fretting wear and electrical contact failure. In addition, the fretting wear volume evolution of both alloys under different fretting cycles is studied. The results show the current load impacts the wear morphology. The wear particles become smaller and the oxide layer becomes stable with the increase of current load. The effect of current load on ECR and temperature is more significant for CuZn40 alloy. The ECR endurance for both materials first increases and then decreases. This is attributed to two competitive mechanisms controlling the evolution of ECR endurance under varied current loads.