EFFECT OF WC-Co ELECTRODE STRUCTURE ON THE RATE OF ELECTROSPARK COATING DEPOSITION

摘要

The effect of such structural features as porosity and grain size on the erosion capacity of electrode materials of the composition 92% WC-8% Co is studied. It is established by calculation and experiment that the high erosion capacity of electrode material is mainly facilitated by its high porosity. A reduction in carbide phase grain size to a size of the order of 100 nm also increases material erosion capacity, but to a markedly lesser extent. Intensification of mass transfer with a reduction in WC grain size and presence of porosity within electrode material gives rise both to a reduction in volumetric heat capacity and thermal conductivity, and also to an increase in its specific electric resistance. All the factors listed above are affected by an increase in local electrode material warming in a spark discharge arc.