ACCELERATION OF POWDER MATERIALS IN AN ELECTROTHERMAL LAUNCHER

The flow of heated dense plasma obtained in the discharge region of an electrothermal launcher can be used for acceleration of powder materi al particles. After being accelerated and heated in the plasma flow, p articles impact substrates and produce coatings with strong adhesion a nd low porosity. An electrothermal launcher system which includes a di scharge unit, a discharge initiation unit, and a powder injector was c onstructed. A theoretical model of the launcher based on one-dimension al nonstationary hydrodynamic analysis of plasma flows was developed. Relationships among the major output parameters (the plasma flow densi ty, velocity, temperature, the particle velocity) on the parameters of the power supply system, the geometrical dimensions of the discharge gap, and the barrel are examined. The construction of accelerator elem ents such as the discharge initiation element which provide a possibil ity of repetitive operation, is described. Experimental results on the plasma flow velocity, the flow pressure upon substrates, plasma tempe rature and powder particle velocity, are presented. Coatings made from metal and nonmetal powders, including diamond powder an metal and non metal substrates, were obtained.