High resolution strain gages for ceramic matrix composites and methods of manufacture thereof

Abstract

Strain gages for use with ceramic matrix composites (CMCs), and methods of manufacture therefore. The strain gages use the CMC as a strain element. For semiconductor CMCs, for example SiC fiber-reinforced SiC CMC, their large gage factor enables high sensitivity, high accuracy strain measurements at high temperatures. By using a single elemental metal such as platinum, or another high temperature conductive material, the strain gages can operate at temperatures over 1600° C. The conductive material is preferably deposited on a dielectric or insulating layer, and contacts the CMC substrate through openings in that layer. The materials can be deposited using thin film vacuum techniques or thick film techniques such as pastes or inks. The strain gages can be configured to measure only the mechanical strain independent of the apparent or thermal strain. The strain gages can be incorporated into a bulk CMC structure during layup, and can optionally measure the strain of only desired fiber weave orientations.