Thermal plasma processing

A review is given of the fundamental aspects involved in material processing using thermal plasma technology. The description of plasma generating devices covers DC plasma torches, DC transferred arcs, RF inductively coupled plasma torches and hybrid combinations of them. Emphasis is given to the identification of the basic energy coupling mechanism in each case and the principal characteristics of the flow and temperature fields in the plasma. Materials processing techniques using thermal plasmas are grouped in two broad categories depending on the role played by the plasma in the process. Only typical examples are given of each type of process. These are grouped under two broad subsections dealing respectively with applications in which the plasma is used as a source of heat in high temperatures, and those in which the plasma is used as a source of chemically active species. The author also deals with plasma diagnostics and mathematical modeling and the role which they can play in the long term development of the technology.>