Formation of structure of WC-Co coatings on aluminum alloy substrate during high-velocity oxygen-fuel (HVOF) spraying

This paper is based on Ref 1 and concerns the mathematical simulation of the structure formation of the WC-Co coating on aluminum alloy (Al-4% Cu) substrate during high-velocity oxygen-fuel (HVOF) spraying. Variations of the solidification velocity, thermal gradient, and cooling velocity in the coating and substrate interfacial region are studied. Formation of the amorphous and crystalline structures in the coating and of the crystalline structure in the substrate interfacial region is discussed. Behavior of the crystal size and intercrystalline distance with respect to the thermal spray parameters is analyzed. Optimal conditions for the development of fine and dense crystalline structure are established. Results agree well with experimental data.