resumo
Multi-carbides/(Al, Si) composites were prepared by a spontaneous reactive melt infiltration technique. B4C and B4C with extra carbon (B4C/C) preforms were infiltrated with Al-Si alloys with Si contents ranging from 36 to 80 wt.%. The infiltration was conducted at temperatures 200 degrees C above the liquidus of the Al-Si alloys. Influence of the composition of the Al-Si alloys on the structure and the correlation of the structure and the mechanical properties of the composites have been studied. The alloys show good infiltration ability to the B4C and B4C/C preforms. The Al-Si alloys reacted with B4C, forming new carbides. Composites composed of carbides of SiC, B4C, AlB12C2, Al3B48C2 and residual Si and Al are obtained. The typical upper values of Vickers hardness and flexure strength are 17 +/- 3 GPa and 328 +/- 8 MPa, respectively, which are provided by the infiltration couple of B4C/l-55 wt.% Si. The fracture mechanism of the composites has also been discussed. (C) 2012 Elsevier B.V. All rights reserved.
palavras-chave
BORON-CARBIDE; WEAR-RESISTANCE; AL; ALUMINUM; CERMETS; AL2O3
categoria
Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering
autores
Wu, HY; Zhang, SC; Gao, MX; Zhu, D; Pan, Y; Liu, YF; Pan, HG; Oliveira, FJ; Vieira, JM
nossos autores
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) and Department of Bilateral, Multilateral and European Relations of FCT/MCTES, Portugal. The authors would like to acknowledge Prof. Jianzhong Jiang and Dr. Xiaodong Wang for their assistance on the testing of elastic modulus of the materials.