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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Liquid phase sintered SiC. Processing and transformation controlled microstructure tailoring

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Author(s):
V.A. Izhevskyi [1] ; L.A. Genova [2] ; A.H.A. Bressiani [3] ; J.C. Bressiani [4]
Total Authors: 4
Affiliation:
[1] Instituto de Pesquisas Energéticas e Nucleares - Brasil
[2] Instituto de Pesquisas Energéticas e Nucleares - Brasil
[3] Instituto de Pesquisas Energéticas e Nucleares - Brasil
[4] Instituto de Pesquisas Energéticas e Nucleares - Brasil
Total Affiliations: 4
Document type: Journal article
Source: MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS; v. 3, n. 4, p. 131-138, 2000-10-00.
Field of knowledge: Engineering - Materials and Metallurgical Engineering
Abstract

Microstructure development and phase formation processes during sintering of silicon carbide based materials with AlN-Y2O3, AlN-Yb2O3, and AlN-La2O3 sintering additives were investigated. Densification of the materials occurred by liquid-phase sintering mechanism. Proportion of alpha- and beta-SiC powders in the initial mixtures was a variable parameter, while the molar ratio of AlN/RE2O3, and the total amount of additives (10 vol. %) were kept constant. Shrinkage behavior during sintering in interrelation with the starting composition of the material and the sintering atmosphere was investigated by high temperature dilatometry. Kinetics of b-SiC to a-SiC phase transformation during post-sintering heat treatment at temperatures 1900-1950 °C was studied, the degree of phase transformation being determined by quantitative x-ray analysis using internal standard technique. Evolution of microstructure resulting from beta-SiC to alpha-SiC transformation was followed up by scanning electron microscopy on polished and chemically etched samples. Transformation-controlled grain growth mechanism similar to the one observed for silicon nitride based ceramics was established. Possibility of in-situ platelet reinforced dense SiC-based ceramics fabrication with improved mechanical properties by means of sintering was shown. (AU)

FAPESP's process: 97/01114-5 - Systemic study for the development of advanced refractory concretes
Grantee:Victor Carlos Pandolfelli
Support Opportunities: Research Projects - Thematic Grants