Dislocation structures which were developed by the compression of α-phase single crystals, oriented for basal slip, were investigated. The compression tests were carried out at an initial strain rate of 10-5 at 1450C in air. Transmission electron microscopy revealed that the Burgers vectors of the dislocations which were introduced by compression were usually those of a type of perfect edge dislocation which belonged to the basal slip system. Dissociation of the perfect dislocations was not observed. On the other hand, it was found to be impossible for the perfect dislocations to be dissociated on the same basal plane, in view of the structure at the nodes of 3 dislocation lines.

Dislocation Structure in Compressed α-Al2O3 Single Crystals. A.Nakamura, T.Yamamoto, Y.Ikuhara: Annual Reports of the Engineering Research Institute of the School of Engineering of the University of Tokyo, 2000, 59, 159-64