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

Abstract

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 was investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), energy disperse X-ray (EDX) spectroscopy, hardmeter and frictional tester. The result shows that the shape 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 reaches the 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 morphology of laser cladding coating and the mechanism of CeO2 on the morphology evolution of WC particle were investigated. Finally, microhardness and wear results show that the coating with 2 wt. % CeO2 has the best mechanical properties.