On the simulation of spark plasma sintered TiB₂ ultra high temperature ceramics: A numerical approach

Spark plasma sintering is a novel sintering technique in the manufacturing of ultra high temperature ceramics. Temperature distribution during the sintering process controls microstructure and consequent thermomechanical properties of manufactured samples. Therefore, the temperature distribution in the spark plasma sintering of TiB₂ is investigated numerically in this work. A pulsed direct electrical current was applied during the sintering process, and current density distribution as well as generated heat, as a result of the Joule heating effect, were obtained at each point. The thermoelectrical governing equations were solved by the finite element method. The obtained temperature contours showed that the heat generation rate is higher at the sample camped to the die, so the heat flow is from the sample center toward the die and finally, the surroundings. The obtained results showed a uniform temperature distribution in the sample, so that a maximum temperate difference concerning the sample center was 75 °C at the sample/die interface at the sintering temperature of 2200 °C. This uniformity is one of the advantages of spark plasma sintering ,which results in a uniform microstructure in the as-sintered sample.