THE COMBUSTION SYNTHESIS OF ADVANCED MATERIALS

This article discusses the versatility of utilizing exothermic combust ion synthesis reactions to produce ceramic, intermetallic, and composi te materials in a one-step process. The emphasis is placed on controll ing the reaction parameters of these exothermic synthesis reactions as a means of controlling the microstructure and properties of the synth esized materials and composites. The application of this technology to the synthesis and control of a selection of advanced materials is dem onstrated (i.e., dense composite materials, uniformly porous or ''foam ed'' ceramics, and functionally graded materials). In addition, the co ntrol of product morphology (e.g., submicrometer particles or whiskers by gas-solid reactions that use vapor phase species deliberately gene rated at the reaction front) is also demonstrated, as is the effect of microgravity processing on some of these reactions.