Growth and microstructure or Al[sub 2]O[sub 3]-SiC-Si(Al) composites prepared by reactive infiltration of silicon carbide preforms

Journal Article · Tue Mar 01 00:00:00 EST 1994 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(94)90261-5· OSTI ID:5149609

Dhandapani, S P; Jayaram, V; Surappa, M ^[1]

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1. Indian Inst. of Science, Bangalore (India). Dept. of Metallurgy

Alumina matrix composites have been grown by directed melt oxidation of an Al-Si-Zn-Mg alloy into sintered SiC preforms. Reaction between melt and the silica layer on the pre-oxidized SiC yields a matrix in which the residual alloy is principally silicon. However, there is no evidence of the formation of Al[sub 4]C[sub 3]. The coarsest particles display the least reaction while porosity increases as the particle size decreases. Thus, owing to the enrichment of silicon, growth rates are retarded compared to those in free space. The microstructure of the oxide is monocrystalline over distances of the order of the inter-particle spacing, however, a new type of growth fault that constitutes an inversion boundary in the Al[sub 2]O[sub 3], has been found. Owing to the substantial reaction between the particle and the melt, the volume fraction of the alloy constituent in the final composite depends sensitively on particle size, in contrast to its relative invariance in directed melt oxidation into inert preforms.

• OSTI ID: 5149609
• Journal Information: Acta Metallurgica et Materialia; (United States), Vol. 42:3; ISSN 0956-7151
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
MICROSTRUCTURE
SINTERING
ALUMINIUM OXIDES
COMPOSITE MATERIALS
SILICON ALLOYS
SILICON CARBIDES
ALLOYS
ALUMINIUM COMPOUNDS
CARBIDES
CARBON COMPOUNDS
CHALCOGENIDES
FABRICATION
MATERIALS
OXIDES
OXYGEN COMPOUNDS
SILICON COMPOUNDS
360602* - Other Materials- Structure & Phase Studies
360601 - Other Materials- Preparation & Manufacture