Abstract <p>A mathematical model of coating formation during supersonic gas-flame spraying (SGFS) is presented, describing the physical processes occurring at the microscopic level when particles of the sprayed material impact the substrate, forming splats. The influence of melt solidification processes on the splat size due to the heat exchange with the substrate is studied. A relationship between the technological parameters of spraying and the performance characteristics of the coating is established. It is shown that the porosity of the coating for poorly wetting materials is inversely proportional to the cube of the flattening factor. Recommendations for optimizing spraying technology (by increasing particle velocity, improving wettability, controlling substrate temperature to reduce thermal stress and minimize porosity) are formulated.</p>