ZHAI Yanxia ¹, LI Zhaomin ¹, SUN Haibin ², ZHANG Yujun ³
(1.Shandong Baona New Materials Co., Ltd. , Laiwu 271114, Shandong, China;
2.School of materials science and engineering, Shandong University of Technology, Zibo 255000, Shandong, China;
3. Key Laboratory for liquid-solid Structural Evolution & Processing of Materials of Ministry of Education, Shandong University,
Jinan 250061, Shandong, China)

Abstract: In this paper, recation sintered B₄C/SiC composite ceramics were fabricated taking phenolic resin and carbon black as carbon sources, and the effects of phenolic resin and carbon black addition ratio on the properties and phase composition were studied. The results show that, in the phenolic resin/carbon black ratio range of 1:8-5:4, B₄C/SiC composite ceramics have high free silicon content and poor mechanical properties at a relatively low phenolic resin / carbon black ratio. When the phenolic resin/carbon black is 4:5, the vickers hardness,flexural strength and fracture toughness were 30.96 GPa, 424 MPa, 5.58 MPa·m^1/2, respectively. The samples were sufficiently dense and the comprehensive performance was the best, and the bulk density was 2.75 g/cm³. The main crystal phases are SiC, B₄C and Si, and Si is uniformly distributed in the continuous phase formed by B₄C and SiC.

Key words: carbon source; reaction sintered; B₄C/SiC ; composite ceramic