Phase evolution and wear resistance of in-situ synthesized (Cr, W)23C6-WC composite ceramics reinforced Fe-based composite coatings produced by laser cladding

Abstract

In this paper, the composite ceramics reinforced Fe-based composite coating was fabricated by laser cladding Fe60+(0–30 wt%)WC mixed powders. The effect of WC on the phase constitution, phase evolution, microhardness and wear resistance of the coatings were investigated. The results showed that only when the addition of WC was 20 wt%, a pores and cracks-free coating was obtained together with the highest hardness and excellent wear resistance. The coating mainly consisted of α-Fe, (Cr, W)23C6 and WC. The microstructure observation indicated that network-shaped (Cr, W)23C6-WC composite ceramics was in-situ synthesized as the reinforcement which was uniformly embedded in the α-Fe dendritic matrix, forming the (Cr, W)23C6-WC composite ceramics composite ceramics reinforced Fe-based composite coating. Combined with the thermomechanical analysis, the phase evolution of the coating was proposed as: WC primary + liquid0→WC in-situ + liquid1→WC in-situ + liquid2+γ-Fe→WC in-situ + M23C6+α-Fe.