LOW ELECTRODE EROSION RATE OF NANOCRYSTALLINE CuCr-50 ALLOY IN VACUUM

Abstract

The CuCr-50 alloy with grain size of less than 50 nm was prepared by the mechanical alloy and hot pressing technique. Its microstructure was examined by XRD, SEM and TEM. The electrode erosion rates of nanocrystalline and microcrystalline CuCr-50 were investigated. It is found that the electrode erosion rate of nanocrystalline CuCr-50 is 24.8 μg/C, much lower than that of microcrystalline CuCr-50 . The main cause is that the vacuum arc shows diffusional features on the nanocrystalline electrode, decreasing the heat flux, current density and the dimensions of the droplets emmited from the cathode.