MAGNESIUM AND AZ91 ALLOY BASED CAST COMPOSITES AND THEIR TRIBOLOGICAL CHARACTERISTICS

Abstract

The composites are tailor made materials designed to possess the required spectrum of properties for a given application. The constituents are chosen and combined to result in a composite which has properties not generally available in the constituents alone. The constituent which is spatially continuous in a composite, is called the matrix and the other constituents which are generally discontinuous, are dispersed in the matrix. The dispersed constituents may have different size, shape and orientations in a matrix. A composite may contain particles with length to diameter ratio around unity or fibers that has high length to diameter ratio. The fibers may be long and aligned along the length of the composite or may be short and aligned or random. Fibers which are expensive constituents compared to particles, may result in anisotropic properties disliked by designers. A composite containing particles dispersed in a matrix, often has isotropic properties and is relatively cheaper and attractive to industries. Solidification synthesis of composites decreases the processing cost of the composites and thus, provides the basic motive for pursuing cast particulate composites.