Metal matrix syntactic foams

Syntactic foams have been attracting considerable attention in recent years due to their potential for weight saving in packaging, armors, and vehicle structures. These foams are synthesized by dispersing hollow particles in a matrix material. Syntactic foams have sufficiently high mechanical properties for use as structural materials. Mg, Al, Pb, Zn, Ti, Ni, Fe and Invar matrix syntactic foams have been studied in recent years. The major advancements related to these materials include synthesis of syntactic foams with density less than 1 g/cm³, synthesis of iron and Invar matrix syntactic foams, and synthesis of metal matrix syntactic foam (MMSF) core sandwich structures. The present chapter reviews the recent state of the art in syntactic foams and presents fundamental principles involved in designing these materials with a desired set of properties. The future trends include advancements in additive manufacturing (AM) methods, development of high performance engineered hollow particles, and development of syntactic foams for dynamic loading conditions.