ABSTRACT
Based on the second-phase morphology, MMCs are divided into discontinuously and continuously reinforced types. Discontinuous reinforcements include SiC, Al2O3, or mixed oxides in the form of particles with AR (the ratio of length to diameter) equaling 1-5, short ‰bers and whiskers (suf‰x/w) with AR in the range of 10-50, or long ‰bers, such as carbon continuous ‰bers and tungsten or stainless-steels wires [2,3] with AR ranging from 50 to 100. The reinforcement AR confers properties that are isotropic for particles, slightly anisotropic for whiskers and chopped ‰bers. Short ‰bers may also be assembled and shaped in preforms for in‰ltration of liquid matrix [1]. Continuous reinforcements, constituted of long SiC or Al2O3 ‰bers with AR >100, have marked anisotropic properties that are most effective when the ‰bers are oriented in the direction of maximum tensile stress.
