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 material particles. After being accelerated and heated in the plasma flow, particles impact substrates and produce coatings with strong adhesion and low porosity. An electrothermal launcher system which includes a discharge unit, a discharge initiation unit, and a powder injector was constructed. A theoretical model of the launcher based on one-dimensional nonstationary hydrodynamic analysis of plasma flows was developed. Relationships among the major output parameters (the plasma flow density, 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 elements such as the discharge initiation element which provide a possibility of repetitive operation, is described. Experimental results the plasma flow velocity, the flow pressure upon substrates, plasma temperature and powder particle velocity are presented. Coatings made from metal and nonmetal powders, including diamond powder on metal and nonmetal substrates, were obtained.<>