INVESTIGATION OF SPRAYING SPOT AND METALLIZATION PATTERN UNDER CONDITIONS OF MICROPLASMA SPRAYING OF COATINGS OF TITANIUM DIOXIDE

摘要

Analyzed is the gained experience in application of gas-thermal technologies in producing of electroconductive, dielectric and resistive coatings for machine building, instrument-making industry and other industry branches. It is shown that the most challenging method for formation of resistive coatings in manufacture of heating elements is a method of the plasma-arc spraying. It was found that during the process of manufacture of the resistive heating elements of small sizes (for example, for radio electronics) by using the method of traditional plasma-arc spraying the losses of material being sprayed, caused by a geometric factor, are increased. In this connection, to increase the degree of applying of sprayed materials, the technology of microplasma spraying is the mostly challenging. The work is aimed at the study of formation of a spraying spot and a metallization pattern under the conditions of microplasma spraying of the titanium dioxide coating. It was found during investigations that the spraying spot of ТiO_2 has a form of ellipse with 6.0-9.2 mm sizes of axes, where the smaller axis is directed along the horizontal line, and the larger one - along the vertical line. Ratio of axes is 1.01-1.47 and depends on the spraying mode parameters. Determined are the losses of material being sprayed due to a geometric factor, which were 53 % in spraying of path of 1 mm width and less than 1 % in spraying the path of 5 mm width.