Metal matrix syntactic foams: Manufacture, matrix material, microstructure, modulus and more

Abstract

To read more about him, turn to page 14. To join TMS, visit www.tms.org/Society/Membership.aspx. Syntactic foams are particulate composite materials that have hollow or porous ceramic particles embedded in continuous polymer or metal matrices. They can have very different behaviors under compression or impact loading conditions, depending on whether the porosity enclosed in the ceramic particles plays a signifi cant role or not. If the ceramic particles are intact during loading, syntactic foams are essentially the same as conventional particulate-reinforced composites, apart from lower densities, and are often called composites instead of syntactic foams. If the ceramic particles in the syntactic foams collapse or deform during loading, however, the theoretical and experimental analyses used for characterizing the mechanical behavior of particulate composites can no longer be applied. In the latter case, syntactic foams behave more like solid foams (porous solids) with some unique characteristics. They deserve to be treated as a distinctive class of materials. Metal matrix syntactic foams have not been studied as extensively as polymer matrix syntactic foams, which have been commercially available for several decades. This is largely because they are more diffi cult and costly to manufacture and the benefi ts accrued from incorporating hollow or porous particles are less pronounced than polymer matrix syntactic foams, especially in terms of mechanical properties. Metal matrix syntactic foams have potential for many applications. The majority of the metal matrix syntactic foams developed so far are intended Metal Matrix Syntactic Foams: Manufacture, Matrix Material, Microstructure, Modulus and More