FRACTURE VERIFICATION OF FINE-GRAIN ISOTROPIC GRAPHITES CONTAINING IMITATIVE DEFECTS SUBSEQUENT TO ROUND-ROBIN TEST OF NONDESTRUCTIVE INSPECTION

Graphite rod specimens containing different sizes of artificial imitat ive defects simulated with carbonized paper, were manufactured experim entally and subjected to a round robin test of non-destructive inspect ion (NDI). The position of each defect in the rod was experimentally c onfirmed by a series of NDIs. This report deals with the results of de structive tests performed as the final step of the robin test. The des tructive test was carried out by diametral compression of disk specime ns cut from several positions of a graphite rod containing the imitati ve defects, and by counting acoustic emission (AE) during the compress ive loading. Based on these results, reliability of various NDIs, and fracture mechanics properties of the imitation defect are evaluated.