Influence of Rare Earth on the High-Temperature Sliding Wear Behavior of WC-12Co Coating Prepared by HVOF Spraying

In this work, WC-12Co coatings were prepared by high-velocity oxygen fuel spraying (HVOF) technology. The high-temperature sliding wear tests at 450, 550 and 650 °C were conducted on a pin-on-disk tribometer, and effects of CeO₂ on the high-temperature wear behavior were investigated. The results showed that CeO₂-modified WC-12Co coating possessed better sliding wear resistance than that of conventional WC-12Co coating at the tested temperatures. The maximum microhardness value of 1333 ± 25HV_0.5 was available at the temperature of 550 °C for CeO₂-modified WC-12Co coating worn track. The oxides formed on the worn surface played a significant role on the wear behavior. W₂C, Co₃O₄ and ratio of CoWO₄/WO₃ dominated the wear behavior of the coating at 450, 550 and 650 °C, respectively.