WETTABILITY OF NICKEL COATED GRAPHITE BY ALUMINUM

Graphite is a very attractive candidate for aluminum-metal matrix comp osites. However, aluminium does not wet graphite, which makes the prod uction of aluminum-graphite composites difficult. Nickel is a material known to be wetted by aluminum. In the presence of a nickel intermedi ate layer between the aluminum and graphite, wetting of the graphite b y aluminum was expected to improve. To determine the wettability of al uminum on nickel coated graphite, the sessile drop technique along wit h a high temperature X-ray setup was used. Aluminum drops on substrate s of graphite, electrolytic nickel, and nickel coated graphite were st udied. Contact angles determined for these samples showed that graphit e is non-wetting while the nickel coated graphite provided better wett ing than electrolytic nickel. The aluminum/substrate interface of the samples was examined microscopically using scanning electron microscop y. (C) 1998 Elsevier Science S.A. All rights reserved.