INVESTIGATION OF TUNGSTEN BORIDE STRUCTURES OBTAINED IN PLASMA-CHEMICAL SYNTHESIS FROM A MINERAL TUNGSTEN-CONTAINING CONCENTRATE

The article presents an analysis of the results of experiments obtained in the process of plasma-chemical synthesis, in a high-frequency plasma flow, of tungsten borides of the W-B system. A method for producing a mixture based on a multicomponent mineral oxide-containing concentrate of the Far East region and boric acid (H3BO3) is described. A schematic diagram of a prototype plasma reactor for the formation of the tungsten boride seed phase in a protective argon medium is presented. The results of the analysis of the chemical and physical properties of tungsten borides of the W-B system obtained under local high-energy exposure to a plasma flow of 10–100 kW/cm2 are presented. Tungsten borides were forming from a multicomponent oxide-containing mineral raw material in one technological cycle. The chemical and phase composition of the synthesis products, including compounds of the W-B system, was determined. The methods of X-ray phase and spectral microanalysis, as well as scanning electron microscopy, were used for identification. Some issues of the nature of the processes and properties of the materials obtained during high-temperature plasma synthesis, the morphology of genesis and formation of boride crystals are considered. During laboratory testing of the obtained material samples, the presence of tungsten borides of the W-B system was confirmed and the presence of phase compounds – WB, WB2 and W2B was established. The prospects of using plasma technologies for the formation of refractory and wear-resistant compounds based on boron and tungsten have been confirmed.