Influence of CeO2 content on WC morphology and mechanical properties of WC/Ni matrix composites coating prepared by laser in-situ synthesis method

Improving the mechanical properties of metal matrix composites (MMCs) by the addition of a ceramic phase is one of the present studying hot spots. Understanding the morphology evolution rule of the ceramic phase during laser cladding is a critical issue to its wider industrial applications. In the present paper, different CeO2 contents with WC reinforced Ni matrix composite coatings were prepared by laser in-situ synthesis technology. The influence of CeO2 content on the WC morphology and the attendant mechanical properties wasinvestigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), energydisperse X-ray (EDX) spectroscopy, hardmeter and frictional tester. The result shows that theshape of WC particles has a close relation to the addition of rare earth oxide CeO2. Specifically, at first, with the increasing CeO2 additions, the aspect ratio of WC particles reachesthe minimum value when 2 wt. % CeO2 is added. Then, the aspect ratio increases with further increasing CeO2 additions. In addition, the effect of CeO2 on macroscopic morphologyof laser cladding coating and the mechanism of CeO2 on the morphology evolution of WCparticle were investigated. Finally, microhardness and wear results show that the coatingwith 2 wt. % CeO2 has the best mechanical properties. (C) 2020 The Authors. Published by Elsevier B.V.