Laser surface remelting of Cu–Cr–Fe contact material

Abstract

Laser surface remelting/resolidifying treatment on a powder metallurgically manufactured Cu–Cr–Fe contact material was studied. Test results showed that a compact remelting/resolidifying layer was obtained with appropriate laser treatment conditions and a suitable surface absorption coating. After such treatment, the Cu–Cr–Fe microstructure was greatly refined and the Cr phase was uniformly dispersed in the Cu rich matrix with fine spherical or near spherical form. Improved compactness and microstructure of the laser remelted Cu–Cr–Fe material yielded increased hardness (by ∼80%), wear resistance, and a reduced friction coefficient compared with the base material. The mechanism of laser strengthening is discussed in relation to the microstructural features of the Cu–Cr–Fe material.