Title: Variations in processing, microstructure and properties of Al/Al₂O₃ composites fabricated by displacement reaction

Authors: Noboru Yoshikawa, Singo Funahashi, Atsushi Kikuchi, Shoji Taniguchi

Addresses: School of Metallurgy, Division of Engineering, Graduate Schools of Tohoku University, 02 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan. ' School of Metallurgy, Division of Engineering, Graduate Schools of Tohoku University, 02 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan. ' School of Metallurgy, Division of Engineering, Graduate Schools of Tohoku University, 02 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan. ' School of Metallurgy, Division of Engineering, Graduate Schools of Tohoku University, 02 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.

Abstract: In order to supply variations in mechanical properties to Al/Al₂O₃ composites by displacement reaction between Si O₂ and molten Al, two processes were attempted to fabricate the modified composites. The first process was to infiltrate Al melt into a partially sintered Si O₇ preform and Al/Al₂O₃ composites were obtained. Molten Al infiltrated into some pores in the preform, which formed thick Al channels in the composite bodies. The mechanical property changed from dutile to brittle, depending on the thickness of these Al channels, which was related to the sintering temperature of Si O₂ preforms. Al-Cu/Al/Al₂O₂ composites were fabricated by reaction between molten Al-Cu alloy and Si O₂. The hardness increased 1.5 times by aging the specimens. Fine precipitates were observed in Al parts in the composite bodies. Their mechanical properties were discussed in relation with the microstructures.

Keywords: aluminium; alumina; displacement reaction; reactive infiltration; mechanical properties; aluminium copper alloy; aging; microstructure.

DOI: 10.1504/IJMPT.2001.005392

International Journal of Materials and Product Technology, 2001 Vol.16 No.1/2/3, pp.32 - 39

Published online: 01 Oct 2004 *

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