Shock interaction of microparticles with the surface and formation of coatings

The features of interaction of the flow of small metallic particles in the solid state with a target are considered in the paper in a velocity range from 200 to 1200 m/s. A regime of coating formation is found to be possible in this range. It is known that surface erosion is observed at lower velocities, and formation of craters and then thermal microexplosions takes place at higher velocities. From the practical point of view, of special interest is the intermediate regime with coating formation at comparatively low temperatures, including those below 0 deg. C. The efficiency of 'cold' spraying is affected by numerous factors: velocity, temperature and concentration of particles, surface, conditions etc. The character of this influence has been studied in gas dynamic jet facilities that produce a high-speed (M = 2.0/3.0) two-phase flow with controlled velocity and concentration of particles, etc