Theoretical study of the powder behavior of porous particles in a flame during plasma spraying

The paper is devoted to study the behavior of porous particles in a flame during plasma spraying. The porous particles were supposed to be a conglomerate of fine precursors with a size of approximately 1 μm. Initially, using iron powder as an example, the sintering time in the solid and liquid phases of such particles was estimated. This time is very long in the case of solid-state sintering (tenths of min) and very short in the case of liquid-phase sintering (few ns). Calculations were then made for Cr2O3 particles of 35 μm and a porosity of 0, 20 and 40% to determine the temperature and melting-front position during particle flight in the flame. Finally, the results were compared with experimental observations for plasma spraying of Cr2O3.