Article ID Journal Published Year Pages File Type
1638314 Transactions of Nonferrous Metals Society of China 2012 8 Pages PDF
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 MPa·m1/2, respectively for SiC(Y) fibres. The SiC(Y) fibres have a higher thermal stability than the SiC(OY) fibres.

Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys