中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 22 No. 4 April 2012 |
（1. Science and Technology on Remanufacturing Laboratory,
Academy of Armored Forces Engineering, Beijing 100072, China;
2. Key Laboratory of Advanced Ceramic Fibers and Composite,
National University of Defense Technology, Changsha 410073, China;
3. Key Laboratory of Fire Retardant Materials of Fujian Province, Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen 361005, China;
4. Materials Science Center, University of Manchester, Manchester M17HS, UK）
Abstract:The yttrium as a sintering aid was introduced into polycarbosilane (PCS) to prepare yttrium-containing PCS (PYCS). Two types of yttrium-containing SiC fibres, the SiC(OY) fibres and the SiC(Y) fibres, were fabricated with PYCS. The structural evolution and the associated properties on changing from SiC(OY) to SiC(Y) fibres during the sintering process were studied. The chemical composition of the SiC(OY) fibres is SiC1.53O0.22Y0.005 with an amorphous structure. The composition of SiC(Y) fibres is SiC1.23O0.05Y0.005. The fibres are composed of a large number of β-SiC crystallites with a size of 50 nm and a small amount of α-SiC crystalline. The tensile strength and fracture toughness of the SiC(OY) fibres are 2.25 GPa and 2.37 MPa·m1/2, respectively, and 1.61 GPa, 1.91 MP, a·m1/2, respectively for SiC(Y) fibres. The SiC(Y) fibres have a higher thermal stability than the SiC(OY) fibres.
Key words: polycarbosilane; yttrium; silicon carbide; fibre
