The Microstructures and Properties of Novel-Type Cu/Cr2Nb Contact Materials Fabricated Mechanically Activated Hot-Pressing

Abstract:

Using Cu, Cr, Nb elemental powders activated by mechanical alloying (MA) for 25 h, the novel-type Cu/Cr2Nb contact materials were fabricated by vacuum hot-pressing at 1000 ℃ for 1 h. The microstructures and the properties of Cu/Cr2Nb contact materials with different compositions were investigated. The results show that Cr2Nb phase can not be synthesized during MA, but can be fully synthesized during vacuum hot-pressing. The prepared Cu/Cr2Nb contact materials have homogeneous and fine microstructures, and Cr2Nb phase sizes fall in several micro. The relative density of Cu/Cr2Nb contact materials with 25%~35% Cr2Nb is comparable with those of CuCr50 prepared by conventional or infiltrating process, but the hardness and conductivity of the former are obviously superior to those of the latter