PROBING MORPHOLOGY AND TOUGHENING MECHANISMS OF HIGH-PERFORMANCE COMPOSITES USING TRANSMISSION ELECTRON-MICROSCOPY

The usefulness of the transmission electron microscopy (TEM) technique in probing the morphology and toughening mechanisms of high performan ce composite systems is demonstrated. TEM provides an effective study of both the morphology and fracture behavior of graphite fiber reinfor ced epoxy and for cyanate composite systems. The failure process in th ese composites can be understood. The TEM technique introduced here is found to be valuable for both fundamental and developmental research in improving both physical and mechanical properties of high performan ce composites. The present work focuses on demonstrating how a composi te can be successfully prepared for TEM investigations. Experimental p rocedures concerning identification and isolation of the crack tip dam age zone, followed by cutting, trimming, staining, and thin sectioning of the composite sample are detailed.