Gas atomized thermal spray powders of various metals and alloys

Thermal spraying is a group of methods which are used to produce for example wear and corrosion resistant coatings on different surfaces. Fine powder of material is fed to high temperature gas flow. The particles accelerate, partially melt and hit to the surface to form a coating. Thermal spraying sets some requirements for the powder. The powder should be able to be fed with constant feed rate and the particle size distribution should be quite narrow to achieve even melt fraction of the particles. For metal alloys gas atomization is the optimum method to produce thermal spray powders. In this paper, results of some powders prepared by laboratory scale medium/high pressure gas atomizer are discussed. Motivation of this work was to study if thermal spray powders could be atomized in suitable particle size without major post processing. Copper and different stainless steels were atomized. Characterization of particle size and morphology were tested. Different aspects of atomization and post processing to increase thermal spray powder quality are discussed.