Publikacje

Abstract:

Tungsten carbide coatings were deposited on steel substrate using a high velocity oxy-fuel (HVOF) spraying method. WC-Co coatings were prepared from commercially available WC-12% Co powders with different powder particle size distribution. Three different nominal powder particle size distributions were used: -45+20 μm, -45+11 μm and -20+5 μm. The microstructures of the coatings were analyzed by light microscopy, scanning electron microscopy and phase composition by X-ray diffraction. Powder particle size distribution was found to be an important parameter, strongly affecting the coating quality. Powder particle size influences porosity and morphology of the splats, as well as phase composition. The smallest porosity and visible lamellar microstructure was achieved using the smallest powder particles. The coating sprayed from powder with the coarsest particle had a higher amount of retained WC. In coating sprayed from powder with the smallest particles, a considerable amount of WC probably has been transformed on W2C and W and part of WC has reacted with cobalt forming amorphous complex phases of CoxWyCz.

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Strona główna > Publikacje

Effect of powder particle size on the structure of HVOF WC-Co sprayed coatings