Rapid sintering of TiB 2 ceramics using Co as sintering aid under high pressure condition

• Published in: Materials science--Poland 2020-09, Vol.38 (3), p.502-507
• Main Authors: Hu, Meihua, Bi, Ning, Liu, Mingming, Gao, Guangjin, Li, Shangsheng, Su, Taichao
• Format: Article
• Language: English
• ISSN: 2083-134X; 2083-134X
• DOI: 10.2478/msp-2020-0050

The improved TiB 2 ceramics were obtained in sintering process at the pressure of 5.5 GPa and temperature of 1550 °C in presence of metallic Co powder. The effect of Co content (ranging from 0 wt.% to 10.0 wt.%) on the phase composition, density, microstructure, Vickers hardness and thermal conductivity of TiB 2 ceramics was analyzed. A small amount of new phase Co 2 B has been created in the reaction of TiB 2 and Co. The relative density of sintered TiB 2 ceramics reached 98.1 %. When the mass fraction of Co increased, the porosity increased, while the hardness first increased and then decreased. The maximal Vickers hardness values were equal to 33.3 GPa or 28.2 GPa when the used load was of 4.9 N or 9.8 N, respectively. The highest reached value of thermal conductivity was 88.9 W˙m −1 ˙ K −1 . The dense TiB 2 ceramics with improved hardness and thermal conductivity were ascribed to the high pressure sintering method and Co sintering aid. High pressure sintering method provides a new way for the preparation of ceramics materials.