The strengthening mechanisms of monocrystals were studied by performing compression tests below and above the peak temperature at which the anomalous strengthening, due to octahedral slip which involved cube cross-slip, changed to primary cube slip. On the basis of a 3-dimensional analysis of the dislocation structures after deformation, it was deduced that the super-dislocations took up various configurations depending upon the test temperature and the initial dislocation structure which was introduced by pre-straining at various temperatures. It was also found that anomalous strengthening appeared over a wide temperature range during octahedral slip under [001] compression. The marked strengthening in this material was attributed to cube cross-slip, and to the resultant complex dislocation structure below the peak temperature and to primary cube slip (which involved dislocation climb) when above the peak temperature.

S.Ueta, K.Jumonji, K.Kanazawa, M.Kato, A.Sato: Philosophical Magazine A, 1997, 75[2], 563-85