The discovered mechanism of erosion of tungsten-copper pseudoalloys in electrospark treatment of the hard alloy VK20 in a carbon containing liquid Is characterized by the formation of sections of high melting phase on the working surface, the phase consisting of a mixture of tungsten and its carbides, and by the predominant action of the electric discharges on these sections. As a rule, copper is removed along the perimeter of the sections of high melting phase. The amount of removed phase is determined (with constant pulse parameters) by the ratio between the components of the pseudoalloy. The concept was advanced of a dynamic surface layer of pseudoalloys during mass effect on them of electrlc discharges in a carbon containing liquid.

The concentration dependences of relative wear and productivity of the tungsten-copper and molybdenum-pseudoalloys in electrospark machining VK20 hard alloy were constructed. These dependences are characterized by the extreme values and are explained by the mechanism of their erosion (described in report 1) in the carbon-bearing liquid with an allowance made for the formation of a mixture of refractory metal and its carbide on the working surface.

Comparative tests of the electroerosion resistance and rate of removal of tungsten-copper composites in different structural conditions were made on a standard production Model 4720 electroerosion profile broaching machine equipped with an ShGI-16-880B wide-range pulse generator. The relatively low resistance of the El'konait composition in machining VK20 sintered carbide may be explained by the strong nonuniformity of its structure and the presence in it of coarse (on the order of 30 μm) grains of tungsten. Composites characterized by high dispersion of the constituent components and a significant degree of uniformity of their distribution possess the highest erosion resistance. The relative wear of these alloys is the lowest (10–15%) of all of those known until now.

A theoretical analysis is made of the densification of porous, viscous Newtonian and non-Newtonian bodies during hot extrusion. Equations are derived expressing the variation of the pressure and discharge energy as functions of relative density, fluidity of the solid phase forming the porous body, the coefficient of elongation, and ram velocity. The equations are applicable also in the limiting case of hot extrusion of a nonporous body.