Effect of Rare Earth on Microstructure and Electrical Breakdown Properties of Cu-Cr Alloys

The electrical breakdown properties of Cu-Cr contact materials with different RE content under 10 Pa vacuum condition were studied.Breakdown mechanism of Cu-Cr contact materials with different RE content were analyzed through comparing the variation of microstructure and hardness.The results show that RE can make the grain finer and increase the dielectric strength.0.20%RE addition made the grain finer than 0.06%RE did and increased the dielectric strength and hardness more obviously,so 0.20%RE addition made the contact material to be interruppted more easily.