Experimental investigation of electrical contact failure mechanisms of spring blade components under lateral fretting at power current levels

In this work, electrical contact degradation characteristics of spring blade components in power connectors under lateral fretting environment is investigated experimentally. The typical evolution processes of contact voltage and temperature at the contact zone as a function of fretting cycles are recorded, together with the surface morphologies and element distribution, a fretting failure map, which could distinguish the failure modes for the combination of load current and normal force is proposed. The wear-dominated disconnection, wear- and melt erosion co-dominated overheating, melt erosion-dominated disconnection and fusion-welding failure modes are summarized. The mechanisms for different erosion patterns at the contact interface are elucidated. The results show that the variations in critical melted radius and cutting force, which depend on current and normal force, are the main reasons for the different degradation modes.