Fabrication of carbon-coated boron carbide particle and its role in the reaction bonding of boron carbide by silicon infiltration

• Published in: Journal of the European Ceramic Society Vol. 42; no. 3; pp. 860 - 868
• Main Authors: Zhang, Cuiping, Xia, Qian, Han, Lingfeng, Zhao, Yiliang, Huang, Nan, Ren, Quanxin, Zhang, Xin, Ru, Hongqiang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2022
• Subjects: Carbon-coated boron carbide particles; Mechanical properties; Microstructure; Reaction-bonded boron carbide; Silicon infiltration; Mechanical properties; Carbon-coated boron carbide particles; Reaction-bonded boron carbide; Microstructure; Silicon infiltration
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2021.10.050

•For the first time prevent the dissolution and reaction loss of boron carbide particles by using carbon-coated boron carbide particles as raw materials in the reaction-bonding of boron carbide by Si infiltration.•A ceramic skeleton of the nano-SiC particles-coated and -bonded boron carbide particles and resultant mechanical properties.•In situ reaction to form nano silicon carbide particles in reaction bonded boron carbide composites. To tackle the dissolution problem of boron carbide particles in silicon infiltration process, carbon-coated boron carbide particles were fabricated for the preparation of the reaction-bonded boron carbide composites. The carbon coating can effectively protect the boron carbide from reacting with liquid Si and their dissolution, thus maintaining the irregular shape of boron carbide particles and preventing the growth of boron carbide particles and reaction formed SiC regions. Furthermore, the nano-SiC particles, originated from the reaction of the carbon coating and the infiltrated Si, uniformly coated on the surfaces of boron carbide particles, thus forming a ceramic skeleton of the nano-SiC particles-coated and -bonded boron carbide particles. The Vickers hardness, flexural strength and fracture toughness of the composites can be increased by 26 %, 45 %, and 37 % respectively, by using carbon-coated boron carbide particles as raw materials.