There exist serious interfacial reactions in squeeze-casting aluminum berat
e whisker reinforced 6061Al composites. To control the spinel reactions a s
ol-gel coating method was used to deposit gamma-Al2O3 and alpha-Al2O3 ceram
ic coatings on aluminum berate whiskers. TEM observations of coating morpho
logy indicate that nanostructured alumina coatings are uniformly deposited
on whisker surfaces, with a thickness of about 30-50 nm. Ball-milling has a
n important effect on final mechanical properties of the composites. gamma-
Al2O3 and alpha-Al2O3 coatings were found to be effective in controlling th
e interfacial reactions, by completely preventing the diffusion of magnesiu
m from matrix/coating interface to coating/whisker interface. (C) 2000 Else
vier Science S.A. All rights reserved.