In situ synthesis of WC ceramic particle reinforced composite coating by GTAW

Abstract

WC ceramic particles reinforced composite coatings were in situ synthesised on the surface of Q235 steel by GTAW processing using mixtures of W, C, Ni, B–Fe and a small amount of Si iron. Microstructures and phase of the coating were analysed by scanning electron microscope, energy dispersive spectrometer and X-ray diffractometer. Furthermore, microhardness and abrasion resistance also were studied using microhardness tester and abrasive tester, respectively. The results showed that the coating was no pore and crack free. The coating consisted of FeNi matrix, M₇C₃, Ni₂Si, Ni₃B, Fe₂B and WC blocky particles. Owing to the uniform distribution of in situ synthesised carbide particles, high hardness and excellent wear resistance were achieved. The maximum hardness of the coating was 1578.8 HV_0.2. The relative wearability of the composite was 23.5 times higher than Q235 steel substrate which showed good wear resistance.

Keywords:

• In situ synthesised
• Wear resistance
• Microstructure
• Properties
• Composite coating