Tribological behavior of alumina reinforced with unidirectionally oriented SiC whiskers

Silicon carbide whisker reinforced alumina ceramic composites were subjected to tribological tests by using bah-on-reciprocating flat geometry at 403 K in order to study wear progress under mild wear regime. Alumina composites were prepared by a modified tape casting followed by lamination, binder removal and hot pressing in order to align the whiskers in tape casting direction. Wear coefficients on three directions were measured; parallel and normal to the tape casting direction on the tape casting surface and normal to lamination direction on surface normal to the tape casting direction. For comparison, samples were prepared by hot pressing the powder mixture. The highest wear rate was obtained in the direction parallel to the tape casting direction and the lowest in the direction normal to lamination direction. The results of this study also indicated that matrix grain size and roughness due to whisker orientation were responsible for variations of wear rate and friction coefficient. (C) 1999 Published by Elsevier Science S.A. All rights reserved.