Fracture verification of fine grain isotropic graphites containing imitative defects subsequent to round robin test of non-destructive inspection Original Research Article

Graphite rod specimens containing different sizes of artificial imitative defects simulated with carbonized paper, were manufactured experimentally and subjected to a round robin test of non-destructive inspection (NDI). The position of each defect in the rod was experimentally confirmed by a series of NDIs. This report deals with the results of destructive tests performed as the final step of the robin test. The destructive test was carried out by diametral compression of disk specimens cut from several positions of a graphite rod containing the imitative defects, and by counting acoustic emission (AE) during the compressive loading. Based on these results, reliability of various NDIs, and fracture mechanics properties of the imitation defect are evaluated.