Morphology and gradient distribution of WC phase in laser-clad NiCrBSiC-WC composite layers

Abstract

The microscopic morphology and distribution of tungsten carbide particles in a laser-clad NiCrBSiC-WC layers were characterized by scanning electron microscopy (SEM). The experimental results showed that there were two effective methods to avoid the stress concentration and cracks. One is the gradient layer with WC hard phase varied gradually from the substrate to the top of the layer using three-step laser cladding. The other is the layer where WC particles, with a marked gradient distribution at interface between the matrix and WC, were uniformly incorporated in the layer by precisely controlling laser-processing parameters. The wear test results show that WC particulates existed at the surface and the excellent interface between WC phase and the matrix in the layer has improved wear resistance. © 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.