Hot zone electrical resistance measurement for health monitoring of SiC and Si-based materials

Abstract

SiC-based materials are good candidates for structural applications at high temperature. However, due to their limited damage tolerance, in-service health monitoring using electrical conductivity measurements would be beneficial. Still, electrical measurements in hot zones on these materials remain a major challenge and require the design of a specific contact material that ensure adhesion of the measurement wires to the material while limiting chemical reactivity with the substrate. TiSi₂-Si eutectic compound was found to be a good candidate for this application. An electrical conductivity (EC) measurement was carried out up successfully to 1300 °C in vacuum on a sintered SiC sample using this contact material. Post-measurement analysis of the contact was carried out, and cracks and SiC growth were observed, but without any impact on the electrical resistance measurement.