Ceramic matrix composites with gradient concentration of metal particles

The design of ceramic-metal composites with a gradient concentration of the metal particles fabricated by the slip casting method is presented. The gradient concentration of the metal particles was achieved through their sedimentation under the action of the gravitational force and a magnetic field. The paper describes the method of calculating the distance between the ceramic particles and indicates the correlation between this distance and the size of the metal particles. Preliminary experimental results of fabricated Al2O3-Fe composites confirmed the calculations. The metal particles, whose density is higher than that of ceramic particles, can undergo gravity-induced sedimentation only when the distance between the ceramic particles is greater than the diameter of these metal particles. With a slip casting containing 50 vol.% of solid phase, no concentration gradient of metal particles occurred. The Fe gradient concentration was achieved when the sedimentation was aided by a magnetic field. (c) 2006 Elsevier Ltd. All rights reserved.