Modern technologies for producing carbon nanostructures are based on many years of experience in the development of coating methods. The latest trends in the formation of carbon nanostructures are associated with complex technological processes of physical and technical treatment, when microstructures are obtained based on traditional methods, which are then completely or partially modified into nanostructures. In this case, the possibility of the formation of a part of nanostructures in a gas flow is considered in order to use them as islands of growth of other nanostructures on the treated surface. The conditions for formation of the specified structures are characterized by the energy state of particles, physical and mechanical properties of particles and substrate materials. The paper presents the results of numerical simulation for determination of velocity and temperature of nanocomposite metal-matrix powder particles in a supersonic nozzle. The necessity to determine parameters of solid particles of powder in a two-phase supersonic flow is determined. Particles velocity and temperature are the crucial parameters which allow for formation of coatings and impact their physical and mechanical properties. The contour plots of velocity and temperature distribution in the nozzle and free space from the nozzle exit to the substrate are obtained. Coating application and its characteristics are considered when selecting coating materials. The numerical simulation is performed for the particles of boron carbide (B$_{4}$C) and nickel (Ni) powders. The dependence of velocity and temperature of nano-sized B$_{4}$C particles in the nozzle on the gas initial conditions is analysed. The obtained results are an important stage in the development of optimal technological processes of coating deposition with selection of a rational ratio between velocity and temperature of the sprayed particles.