MODELING OF ELECTRICAL HEATING AND DENSIFICATION OF BORON CARBIDE-BASED MATERIALS DURING SINTERING IN A HIGH PRESSURE APPARATUS

Abstract

Computer modeling of electric heating and densification of boron carbide based materials during sintering in a high-pressure apparatus (HPA) at a temperature of 2073 K and a pressure of 2500 MPa was performed. The Skorokhod–Olevskyi–Stern model of compaction of porous materials was used, taking into account the kinetics of grain growth during sintering. Modeling was performed using the finite element method. It was established that the temperature drop in the sample remains almost constant during the holding at the sintering temperature. It is shown that the duration of the compaction process of the entire sample during sintering in HPA is 10 times shorter compared to the duration of compaction during high-speed sintering and several tens of times shorter than during the SPS process. It is also shown that the grain growth of the sample during the sintering process in HPA is insignificant. At the stage of heating and holding, the inhomogeneity of the temperature field affects the inhomogeneity of the size distribution of the sample grains; the inhomogeneity of the distribution of grain sizes increases with the holding increasing.The results of grain size growth modeling correlate with the results of laboratory experiments.