Investigation of Field Effects in Combustion Synthesis

University Of California-Davis, Davis CA

Investigators

Abstract

This is an investigation of the influence of an electric field on combustion synthesis. The effects of an electric field through thermal (Joule heating), mass transport (electrotransport), and capacitive (dielectric) contributions are studied. The work includes both solid-solid and solid-liquid reaction systems. Effects of both the magnitude and direction of AC current on the nucleation and growth of product layers at the interfaces are determined quantitatively. Models are based on mass transport flux equations modified by electrotransport (electromigration). The process of ignition by an electric field in also studied; a better understanding of product formation and homogeneity is desired. The technological implications of this work are large: synthesis of materials systems that are achievable only by activated SHS (self-sustained high-temperature synthesis); modification of composition and morphology of SHS products including nanomaterials; and modification of interfacial interactions in such applications as functionally graded materials (FGMs), thermal barrier coatings (TBCs), and chemical barrier coatings (CBCs); and one-step synthesis and densification of ceramic materials.