Surface and cross–section characteristics and friction–wear properties of high velocity oxy fuel sprayed WC–12Co coating

Abstract

A WC–12Co coating was sprayed on H13 hot work mould steel using a high velocity oxy fuel (HVOF). The surface and cross–section morphologies, chemical compositions, and phases of obtained coatings were analyzed using a field emission scanning electron microscope (FESEM), energy dispersive spectrometer (EDS), and X–ray diffraction (XRD), respectively. The friction–wear properties were investigated using a wear test, the wear mechanism of WC–12Co coating was also discussed. The results show that the WC–12Co coating primarily is composed of WC hard phase with high hardness and Co as a binder, which is evenly distributed on the coating surface, no atom–rich zones. There is no W3O phase appearing in the HVOF spraying, showing that the WC–12Co coating has high oxidation resistance, the new phases of W2C and C are produced due to the decarburization of WC. The coating thickness is ~200 μm, which is combined the substrate with the mechanical binding and local micro–metallurgical bonding. The average coefficient of friction (COF) of WC–12Co coating is 0.272, showing good friction performance, the wear mechanism is primarily abrasive wear, accompanied with fatigue wear.

The Effect of High-Velocity Air-Fuel WC-12Co Coatings on the Wear and Corrosion Resistance of TC18 Titanium Alloy

“…A large amount of the hard WC phase in the coating is the main reason behind the improvement in the hardness and wear resistance of the coating. In a study by Hui et al [32], a small W2C peak was found in the XRD atlas of the WC-12Co coating, indicating that the decarbonization reaction of WC occurs in HVOF spraying. No new WC phase was found in this study, indicating that the coating was not oxidized or decarburized and the coating quality is great.…”

Experimental and computational investigation of FGM coated cylinder liners prepared using HVOF technique

“…Various HVOF hard-coated materials, encompassing metallic composites, nitrides, borides, and carbides, find widespread application across diverse industries. These industries include natural gas and petroleum, power plants, automotive, and mould manufacturing, attesting to the versatility and utility of HVOF coatings [7][8][9][10][11][12][13].…”