Microstructure and wear resistance of Co-based/Cr₃C₂ coatings with CeO₂

ABSTRACT

Metal–ceramic composite powders consisted of the single self-fluxing alloys reinforced with ceramic particles such as WC, Cr₃C₂ and TiC. Co-based/Cr₃C₂ composite coatings with CeO₂ were prepared on Cr12MoV surface by laser cladding process. The dilution ratio, microstructure and phases of the coatings were analysed by scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy and X-ray diffraction. Microhardness and wear behaviour were measured by digital microhardness tester and dry sliding wear tester, respectively. The obtained results demonstrated that adding CeO₂ to the coatings could result in the decrease in dilution ratio. CeO₂, with the appropriate amounts, could validly refine the grain and reduce interplanar spacing. Phases of the coatings principally included γ-Co, Cr₂₃C₆ and some undissolved Cr₃C₂. New compounds Ce₂Co₁₇, Ce₆Ni₇Si₄ appeared with CeO₂ addition. However, the specific shape of undissolved Cr₃C₂ particles was hardly observed. Furthermore, both microhardness and wear resistance of the coatings were improved after adding CeO₂.

KEYWORDS:

• Metal–ceramic composite coating
• CeO₂
• grain refinement
• dilution ratio
• wear behaviour

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Natural Science Foundation of China under Grant (No. 51405335 and No. 51575383).