Influence of B4C, SiC and Si3N4 Additions on Microstructures and Selected Properties of Titanium Nitride Matrix Materials Obtained by HPHT Method

Abstract

The paper presents the results of the High Pressure and High Temperature (HP-HT) sintering and investigation of Ultra High Temperature Ceramics (UHTC) composites of titanium nitride matrix. The aim of this studies were to determine the influence of additives on the ceramic phase composition, microstructure and selected properties. Three different kind of mixtures were prepared. 8 to 22 wt% B4C, SiC and Si3N4 were added. Composites were sintered under high-pressure high-temperature conditions (HP-HT) using a Bridgman-type apparatus under pressure about 6 GPa. Materials were sintered at the range of 1450 to 1690 ° C, duration of sintering was 60s. The phase composition, microstructure, and the apparent density, Young's modulus, hardness and fracture toughness KIC (HV), using the Vickers indentation method were examined. Sintered titanium nitride with the 22 wt% silicon carbide participation was characterized the best physical and mechanical properties. For this material the relative density is 99%, the Young's modulus 435 GPa, Vickers hardness 18.3 GPa HV1 and fracture toughness 5.5 MPa∙m1/2.