Sintering of TiB2 ceramics

Abstract

Purpose: Titanium diborides (TiB2) ceramic is particularly interesting because it exhibits high elastic modulus and hardness as well as high thermal conductivity. The interest in TiB2 ceramic increased enormously due to these properties but applications seem to be limited due to difficulties during densification process. In the experiment the TiB2 compacts was obtained using HP-HT method. The aim of this study is to work out and optimize the sintering densification process of TiB2 ceramics. Design/methodology/approach: The high temperature-high pressure (HT-HP) Bridgman type apparatus was used for densification method of TiB2 powder. Ceramics were sintered at pressure of 7.2 ± 0.2 GPa and temperature at 1500-2300oC ± 50oC. The duration of sintering was 60 seconds. In order to investigate the structure changes, the optical and scanning electron microscope was used. Mechanical properties were determined by Vickers hardness. Young modulus measurements were carried out using ultrasonic method. Findings: The TiB2 ceramics was obtained without using sintering agents. The properties and structure of TiB2 ceramics strongly depend on conditions of sintering process. The application of the temperature of 1500oC±50oC and pressure of 7.2 ± 0.2 GPa and time of 60 seconds permits to obtain the TiB2 ceramics without cracks. Practical implications: The TiB2 ceramic might be used for production of composites. From a practical position it is important to optimize the sintering densification of TiB2 ceramic. Originality/value: The TiB2 ceramics were formed using HP-HT technique without the use of additives. This method of sintering for TiB2 ceramics is original one.