Hot pressing of transition metal nitrides and their properties

1. On the basis of a study of the sintering of transition metal nitride powders by the hot-pressingtechnique, suitable process parameters were established enabling dense nitride parts to be produced. 2. The energy of activation for viscous flow in hot pressing was determined and found to be much less than the energy of activation for the volume self-diffusion of atoms in the metallic sublattices of the compounds investigated. 3. Using hot-pressed specimens, measurements were made of the electrical resistivities and Hall coefficients of the nitrides. The electrical conductivity of nitrides of the transition metals of Groups IV–V has a metallic character; the effective current carrier concentration, calculated on the basis of the singleband model, is of the order of 1023 cm−3. The experimental data obtained on the physical properties of the nitrides show that hot-pressing densification yields practically nonporous materials which are identical in properties with the bulk nitrides.