resumo
SiC whisker reinfored carbide-based composites were fabricated by a reactive infiltration method by using Si as the infiltrate. Rice husks (RHs) were pyrolyzed to SiC whiskers, particles and amorphous carbon, and were then mixed with different contents of B4C as well as Mo powders. The mixtures were molded to porous preforms for the infiltration. The SiC whiskers and particles in the preform remained in the composite. Molten Si reacted with the amorphous carbon, B4C as well as Mo in the preform during the infiltration, forming newly SiC, B-12(C,Si,B)(3) as well as MoSi2. The upper values of elastic modulus, hardness and fracture toughness of the composites are 297.8 GPa, 16.8 +/- 0.8 GPa, and 3.8 +/- 0.2 MPa m(1/2), respectively. The influence of the phase composition of the composites on the mechanical properties and the fracture mechanism are discussed. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
palavras-chave
SILICON-CARBIDE; MECHANICAL-PROPERTIES; CERAMIC COMPOSITES; MICROSTRUCTURE; HULLS
categoria
Materials Science
autores
Wu, HY; Gao, MX; Zhu, D; Zhang, SC; Pan, Y; Pan, HG; Liu, YF; Oliveira, FJ; Vieira, JM
nossos autores
Filipe José Alves de Oliveira
Investigador Principal
Joaquim Manuel Vieira
Professor(a) Jubilado(a)Grupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
agradecimentos
The work was supported by The Science and Technology Program of Zhejiang Province, China (No. 2008C24002).