Combustion synthesis of Zr-Si intermetallic compounds

SHS experiments have been performed starting from the elemental compositions corresponding to all the Zr-Si intermetallic compounds. Analysis of the products shows that the Si rich compositions give, as the major product components, ZrSi2 and ZrSi, and the Zr rich composition the high temperature phase Zr5Si3. Melting of silicon has been identified as the triggering step for the combustion process. Once initiated the reaction involves solid (Zr)-liquid (Si) or liquid-liquid interactions. The phase formation is then controlled by kinetic parameters rather than thermodynamic ones. Solid-solid interaction can play an important role in the pre- and post-front regions; these have been studied through diffusion couples experiments. (C) 1999 Elsevier Science S.A. All rights reserved.