Researches Structure and Properties of Self-Fluxing Coating, Obtained by Air-Plasma Spraying
The structural features of self-fluxing coatings obtained by air-plasma spraying with a unit of annular injection of powder are discussed in the article. It is shown that the application of an annular injection unit makes it possible to increase significantly the efficiency of particle heating in contrast to the point injection of a powder into the plasma jet. It is shown by optical and scanning electron microscopy that the major part of particles which form the coating is in a molten or plasticized condition in the plasma jet. It is revealed by transmission electron microscopy that a high cooling rate of these particles contributes to the formation of the γ-submicrocrystalline supersaturated Ni-based solid solution with an average grain size of 80 nm. To provide high technological and tribological properties it is necessary to carry out plasma spraying at an arc current less than 170 A.
E. Kornienko et al., "Researches Structure and Properties of Self-Fluxing Coating, Obtained by Air-Plasma Spraying", Applied Mechanics and Materials, Vol. 698, pp. 405-410, 2015