During the plasma spheroidization process powders undergo different changes intheir microstructures and crystal phases.In this paper,simple calculation of heat transfer betweenthe plasma and a suspended particle was performed based on three hypotheses for the purposeof guiding experiments.Experimental investigation of the crystal phases and microstructuralchanges during the plasma processing was made using silica,alumina and nickel powders as startingmaterials.It has been revealed from the experimental results that these materials undergo differentchanges in crystal phases and microstructures,and these changes are essentially determined bythe structures,properties and aggregate states of the starting materials.
