Synthesis and properties of ceramics in the SiC-B4C-MeB2 system

The effect of impurities and additives of titanium and zirconium borides on the structure and mechanical properties of SiC - B4C ceramics over a broad temperature range has been investigated. The ceramics was fabricated by ho t pressing without a protective medium. Introduction of borides is accompan ied by improvement in all the studied mechanical properties at room tempera ture, and the nature of hardening of the ceramics is practically independen t of the type of SiC powders used. At high temperatures, the mechanical beh avior of the ceramics is determined by the impurity composition: the cerami cs obtained using abrasive powders loses strength beginning at 600 degreesC , while using powders with decreased impurity content makes it possible to preserve the strength of the material up to a temperature of 1400 degreesC.