Electrical Resistance as a Nondestructive Evaluation Technique for SiC/SiC Ceramic Matrix Composites Under Creep-Rupture Loading

Authors


  • Based in part on the thesis submitted by C. E. Smith for the M.S. degree in mechanical engineering, The University of Akron, Akron, OH, 2009.

  • This work was financially supported by the NASA Glenn Research Center ARMD Hypersonics program, under Grant No. NNX07AN56H.

Abstract

SiC/SiC ceramic matrix composites under creep-rupture loading accumulate damage by means of local matrix cracks that typically form near a stress concentration, such as a 90° fiber tow or a large matrix pore, and grow over time. Such damage is difficult to detect through conventional techniques. This study demonstrates that electrical resistance is a viable method of monitoring and inspecting damage in SiC/SiC composites at high temperature. Both interrupted and uninterrupted creep-rupture experiments were performed at 1315°C and 110 MPa with in situ resistance measurements. A linear relationship was found between resistance and cumulative crack depth.

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