Oxidation kinetics of boron carbide ceramic under high gamma irradiation dose in the high temperature

Abstract In the presented work, high purity boron carbide (purity of 99.9%, and bulk density 1.8 g/cm3 at 20 °C) compounds were gamma-irradiated at dose rate of D = 30 rd/sec using Co60 gamma source. The irradiation of the samples at different gamma doses (5·109; 1·1010; 1.5·1010 and 2·1010 Mrd) was carried out at room temperature and atmospheric pressure. The Differential Scanning Calorimetry (DSC) was used to study the solvothermal chemical reaction mechanisms of boron carbide from room temperature up to 900 K and the oxidation kinetics, rate of oxidation diffusion (plots of Jander), depth of oxidation and activation energy from 900 ≤ T ≤ 1250 K after gamma irradiation at different gamma absorption doses. The depth of the gamma irradiation dose on the surface determined the “critical limit” for the thin oxide layer for boron carbide. Also, depths of gamma irradiation dose is calculated activation energy by the Arrhenius plots. The activation energy was found to increase from 99.59 J mol−1 to 102.93 J mol−1 as the gamma irradiation dose increased from 5·109 to 2·1010 Mrad.