Temperature and current density distributions at spark plasma sintering of inhomogeneous samples

We analyze the effect of inhomogeneity in the properties of a material on the conditions of obtaining thermoelectrics by spark plasma sintering. Inclusions localized and distributed over the volume of materials with different values of electric and thermal conductivities are considered. It is found that the presence of macroscopic inhomogeneities changes the current density distribution in the cross section of the sample being sintered. It is shown that inhomogeneity in the properties of materials during sintering do not substantially affect the temperature field in the sample at the macroscopic level, but change the current density distribution profile. The ranges of variation of the current density in the regions with inhomogeneous electric and thermal conductivities are determined for various types of macroscopically inhomogeneous inclusions and their distribution. The applicability of various models for describing spark plasma sintering is considered.