Synthesis of Polydisperse Boron Carbide and Synthesis of a Ceramic on Its Basis

Resumo

Results obtained in a study of the process of synthesis of a polydisperse boron carbide powder (average particle size 2.10 µm) characterized by a broad particle size distribution are presented. The process in which a ceramic is produced from the thus synthesized boron carbide by hot compaction was also analyzed. In some cases, a sintering additive, highly dispersed chromium carbide powder (average particle size 7.13 µm), was used. The hot compaction was performed in argon at moderate parameters: pressure 35 MPa and temperature 1950°C. The porosity and water-absorption capacity of the samples obtained are very low and do not exceed 0.02%. The average values of the bending and compression strengths were 406 and 1553 MPa, respectively. A microhardness of about 42 GPa was reached in sintering of boron carbide. The microhardness in sintering of boron carbide with addition of chromium carbide was 45–46 GPa.