Microstructure and Wear Performance of Inconel 718 Composite Coatings Reinforced with Multi-size and Content WC-Co Fabricated by Laser Cladding

Laser cladding provides the feasibility for fabricating various ceramic-reinforced metal-matrix composite coatings, in which the particle size and content of the reinforcing particles play a crucial role in the properties of the cladding. In this paper, to improve the hardness and wear resistance of Inconel 718 coatings, a series of composite coatings were prepared by laser cladding and the effects of WC-Co grain size and content on the macrostructure, microstructure, phase composition, and mechanical properties of Inconel 718 coatings were revealed in detail. The results showed that with the increase in WC-Co content, multiple carbides coexisted in the coating, the grain size became smaller, and the cracking susceptibility increased. The coatings containing 10-55 mu m WC-Co particles have higher grain refinement and higher hardness and better plasticity, but also higher coefficient of friction (COF) values. Based on the increased hardness, the coatings containing 40-120 mu m WC-Co particles showed better wear resistance, with a 70.3% reduction in wear volume compared to pure Inconel 718 with 30% WC-Co content. The wear mechanism of each coating was dominated by abrasive wear.