Comparative analysis of tribological behavior of plasma- and high-velocity oxygen fuel-sprayed WC-10Co-4Cr coatings

Abstract

Purpose: The purpose of this study is to prepare WC-10Co-4Cr coatings using two processes of plasma spraying and high-velocity oxygen fuel (HVOF) spraying. The decarburization behaviors of the different processes are analyzed individually. The microstructural characteristics of the as-sprayed coatings are presented and the wear mechanisms of the different WC–10Co–4Cr coatings are discussed in detail. Design/methodology/approach: The WC–10Co–4Cr coatings were formed on the surface of Q235 steel by plasma and HVOF spraying. Findings: Plasma spraying causes more decarburizing decomposition of the WC phase than HVOF spraying. In the plasma spraying process, η(Cr25Co25W8C2) phase appears and the C content decreases from the top surface of the coating to the substrate. Practical implications: In this study, two WC–10Co–4Cr coatings on Q235 steel prepared by plasma and HVOF spraying were compared with respect to the sliding wear behavior. Originality/value: The wear mechanisms of the plasma- and HVOF-sprayed coatings were abrasive and oxidation, respectively.