Properties of WC-10Co4Cr Coatings Sprayed by HVAF

WC-10Co4Cr coatings were prepared by high velocity air fuel (HVAF) thermal spraying and high velocity oxygen fuel (HVOF) thermal spraying,respectively.The phase composition and microstructure of different powders and coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The micro-hardness,porosity and erosion resistance were compared between different coatings.Erosion failure mechanism of the coatings in sandy stream was analyzed as well.The results indicate that the coating prepared by HVAF with good density was superior to the coating prepared by HVOF in micro-hardness and erosion resistance.The refined WC grains could improve the micro-hardness and toughness of the coatings,resulting in the increase of micro-cutting resistance and anti-fatigue spalling properties,and thus enhance the erosion resistance for the coatings.