Pressureless liquid-phase sintering of B4C with MoSi2 as a sintering aid. Issue 10 (July 2019)

• Record Type: Journal Article
• Authors: Wang, Shuai; Gao, Shuaibo; Xing, Pengfei; Nie, Dan; Yan, Shu; Zhuang, Yanxin
• Is Part Of: Ceramics international. Volume 45:Issue 10(2019)
• Page Start: 13502
• Page End: 13508
• Publication Date: 2019-07
• Subjects: B4C -- MoSi2 -- Pressureless -- Liquid-phase sintering -- Toughing mechanism; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.04.054
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Pressureless sintering of B4 C with MoSi2 (5–30 wt%) as a sintering aid was carried out at 1600–2260 °C in vacuum. The phase compositions, relative density, microstructures and mechanical properties of the obtained ceramic composites were investigated. Results indicate that MoSi2 can react with B4 C to in-situ form Mo2 B5 and SiC below 1600 °C. Mo2 B5 will gradually transform to MoB2 with the further increasing temperature. Liquid-phase sintering of B4C is realized at about 2150 °C and the formed liquid phase fills the pores in the matrix, enhancing the densification of the composites. The relative density, fracture toughness and hardness of the samples with 30 wt% MoSi2 sintered at 2260 °C reach 96.5%, 3.98 MPa m 1/2 and 28.1 GPa, respectively. The high-toughness second phases and the coexistence of transgranular and intergranular fracture have a synergistic effect on improving the overall fracture toughness of the ceramic composites.