ABSTRACT

Particle reinforced metal matrix composites are an important new class of materials that have potential for use in a wide variety of applications. The industries considering these materials range from automotive to aerospace, from electronics to sporting goods [1,2]. The characteristics that make particle reinforced metals of interest to these industries are also quite varied and include excellent thermophysical properties, good tribological characteristics, and high strength-toweight and stiffness-to weight ratios. Perhaps one of the most important attributes of these and other composite materials is that their individual constituents can be selected such that the combined properties of the composite are specifically tailored for a particular application. One can add silicon carbide particles to aluminum to reduce a material's thermal expansion coefficient, but alumina particles might be a better choice for improving wear resistance. Increasing the amount (termed volume fraction) of SiC particles in an aluminum composite increases its stiffness however it also tends to decrease its ductility. Balancing the specific properties needed for a particular application requires a careful assessment of the critical properties for that application as well as an understanding of the means of obtaining this mix of properties in a single composite. The goal of this chapter is to provide practical tools to assist the practicing engineer to design or select an appropriate particle reinforced metal matrix composite for a particular application. The properties that are emphasized are the physical properties, specifically elastic and thermal properties, and strength-related properties, specifically tensile

Fig. 1. Typical microstructure of a particle reinforced aluminum composite (2080AI/SiC/20p) at magnifications of (a) 500x and (b) 2000x.