Spark plasma sintering of fine-grained tungsten alloys W + 10%Ni

The mechanisms of fast Spark Plasma Sintering (SPS) of a tungsten alloy W + 10 wt.%Ni have been studied. Particles with the “W core – Ni shell” structure (referred to as W@Ni) were obtained by deposition of nickel onto the surface of submicron tungsten particles. To reduce the concentration of oxygen and oxides, W@Ni powders were subjected to annealing in hydrogen at different temperatures. The phase composition, microstructure parameters and mechanical properties of the obtained samples were studied. It is shown that the samples have a high relative density and small grain size. The mechanisms of rapid sintering of fine-grained W + 10 wt.%Ni alloys have been determined. It is shown that the activation energy of high-speed sintering of submicron W@Ni powders is close to the activation energy of grain-boundary diffusion.