Innovative Quality Control Assessment Methods for Ceramic Matrix Composite (CMC) Components

The fabrication of ceramic matrix composites is a multi-step process requiring careful monitoring and control at each step in the processing cycle. Consistent, high quality components can only be reliably reproduced if a firm foundation is provided by initially insuring the uniformity and consistency of the reinforcing yarns. Although considerable effort has been invested in developing NDE suitable for characterizing green as well as fully consolidated components, much less has been done to characterize the reinforcing yarns. In this Phase I program, we develop and implement in-line testing methods to characterized silicon carbide yarns. Methods are formulated to test both sized and un-sized yarns at the initial stages of the processing cycle. Experiments are performed relating various yarn defects to those found in the partially finished and finished composites. Integration of yarn testing methods into the normal manufacturing process will pay a large dividend in cost reduction, result in more consistent component performance (improved quality), and lead to improved process and product understanding.