J. Mater. Sci. Technol. ›› 2016, Vol. 32 ›› Issue (7): 633-638.DOI: 10.1016/j.jmst.2016.01.009

• Orginal Article • Previous Articles     Next Articles

Enhanced Fracture Toughness of Pressureless-sintered SiC Ceramics by Addition of Graphene

Qisong Li1, 2, Yujun Zhang1, 3, *, Hongyu Gong1, 3, Haibin Sun1, 3, Wenjie Li4, Li Ma1, 3, Yanshuang Zhang1, 3   

  1. 1 Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials of Ministry of Education, Shandong University, Jinan 250061, China; 2 School of Materials and Chemical Engineering, Zhongyuan University of Technology, Zhengzhou 451191, China; 3 Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, Shandong University, Jinan 250061, China; 4 Shandong Baona New Materials Co., Ltd., Laiwu 271114, China
  • Received:2015-09-16 Revised:2015-10-22 Online:2016-07-10 Published:2016-10-10
  • Contact: Corresponding author. Prof., Ph.D.; Tel.: +86 531 88399760; Fax: +86 531 88399760. E-mail address: yujunzhangcn@sdu.edu.cn (Y. Zhang).

Abstract: To enhance the fracture toughness of pressureless-sintered SiC ceramic, graphene was introduced as an additive. The effects of graphene contents on the fracture toughness, bending strength, micro-hardness, phase compositions, and microstructure evolutions of the SiC ceramics were investigated in detail by scanning electron microscopy, energy dispersive X-ray spectroscopy, and metallographic microscopy. The fracture toughness, bending strength and micro-hardness increased initially, and then decreased with the graphene content increasing from 0 to 5.0 wt%. The highest fracture toughness of 5.65?MPa m1/2 was obtained for sample with 1.0 wt% graphene sintered at 2130?°C for 1?h in Ar, which was about 22.6% higher than that of SiC sample without graphene. In addition, the highest bending strength and micro-hardness of 434.14?MPa and 29.21 GPa corresponded to the SiC samples with graphene content of 0.5 wt% and 2.0 wt%, respectively.

Key words: SiC, Graphene, Fracture toughness, Bending strength, Micro-hardness