Effect of WC and CeO2 on microstructure and properties of W-Cu electrical contact material

W-Cu alloys with an individual addition of WC and CeO2 particles were prepared by means of powder metallurgy and infiltration, and the effect of WC and CeO2 individual addition on microstructure and properties of W-Cu alloys was investigated. The results show that W-Cu alloys with a separate addition of 1.5 wt% WC and 0.5 wt% CeO2 have desired properties, but an excessive addition decreases hardness and electric conductivity. The vacuum electrical breakdown tests show that the individual addition of WC and CeO2 results in the enhancement of the breakdown strength and decrease of the chopping current. The microstructual analysis of W-Cu alloys with WC or CeO2 addition after vacuum electrical breakdown 50 times shows that the vacuum electrical arcs spread on the cathode surface. Meanwhile, W-Cu alloys with WC or CeO2 addition has a slight splash of molten copper, a less amount of cathode craters, and fine dispersed cathode craters on the entire surface of W-Cu alloys. (c) 2009 Elsevier Ltd. All rights reserved.