Preparation and arc erosion behavior of AgNi10 contact material with different allotropes of carbon addition

Abstract

AgNi10 contact materials adding carbon nanotubes (CNTs), nanographene sheets (GNPs), and graphite(Gr) were fabricated via powder metallurgy method. To investigate the influence of different allotropes of carbon addition on microstructure and properties of AgNi10 contacts, the arc erosion behavior was tested under a DC resistive load of 24V/20A. The results indicate that uniformly dispersed CNTs and GNPs present obvious strengthening effect while Gr leads to strength reduction of AgNi10 contacts. The contacts adding CNTs and GNPs show well-scattered and stable arc. Material transfer from cathode to anode was observed but the mass change is less than that of the contact without addition. The contacts with CNTs and GNPs addition show smooth surface without deep crater on the cathode or sharp tip on the anode. Moreover, no obvious splash of molten Ag and Ni was observed. Anti-welding performance is improved with all the carbon allotropes. The contact added GNPs presents the best arc erosion performance with average arc time as 14.7 ms, average contact resistance as 4.51mΩ, and maximum welding force as 38cN.