Development of Scanning Microwave Technology for Ceramics in Extreme Environments
Advanced ceramic materials are required to meet increasing high temperature demands of components in advanced propulsion engines for high performance aircraft as well as increasing structural demands in ceramic-composite armor. Monitoring the structural performance of these advanced ceramic materials presents challenges. Recently a new technology, Evisive ScanTM, based on microwave interferometry has been developed that allows condition monitoring. The internationally patented Evisive Scan™ method (1, 2, 3, 4, 5, 6), utilizes microwaves to interrogate dielectric materials. The microwaves are reflected at areas of changing dielectric constant. The reflected energy and the interrogating beam are combined to form an interference pattern which is measured in the transceiver as a signal voltage. The signal voltage is sampled at many positions in the inspection area. This point cloud is displayed as an Evisive Scan™ image, which presents volumetric detail of the inspected part. Over the past two years the technology has been demonstrated on Ceramic Matrix Composites and has shown to be an efficient measurement of porosity and manufacturing defects. The method has also been demonstrated to be applicable to ceramic composite armor made of monolithic ceramic tiles in complex, multilayer structures.
Pietro VINCENZINI, Sheldon WIEDERHORN and Paolo COLOMBO
J. R. Little Jr. "Development of Scanning Microwave Technology for Ceramics in Extreme Environments", Advances in Science and Technology, Vol. 65, pp. 153-162, 2010