Microstructure and properties of induction brazing nickel base/WC composite coating

BNi-2/WC composite wear-resisting coating was prepared on carbon steel by the method of induction brazing. The microstructure and phase composition of the composite coating were analyzed, and the bonding strength and wear-resisting performance of the coating were tested. During the process of induction brazing, the tungsten carbide partially dissolves and reacts with the filler metal alloy to form NiW compound phase, which realizes the metallurgical combination of tungsten carbide and filler metal alloy. The matrix of the filler metal alloy consists of Ni solid solution and Ni₃B/Ni₃Si eutectic phase, and the metallurgical diffusion reaction occurs between the filler metal alloy and the steel matrix. The mechanical analysis results show that the self-strength of the composite coating reaches 140 MPa and the bonding strength of the filler metal alloy to the steel matrix reaches 360 MPa. The dry sand rubber wheel wear testing machine showed that the coating weight loss was only 0.2824 g, which was only 1/5 of the weight loss of 65 Mn matrix under the same conditions.