DISLOCATION-STRUCTURE IN L1(2) MN-STABILIZED AL3TI DEFORMED BETWEEN 77 AND 873 K

Polycrystalline samples of L1, Mn-stabilized Al3Ti were deformed in co mpression from low temperature to the temperature of the flow stress p lateau. The fine structure of the superdislocations was analyzed under weak-beam conditions with particular attention paid to the operating glide systems at different temperatures. The dissociation mode of the dislocations was also addressed in order to discriminate between antip hase boundary-coupled dislocations and Superlattice Intrinsic Stacking Fault (SISF)-coupled partial dislocations. The existence of a strong Peierls effect on undissociated (110) dislocations during deformation at 573 K is reported, as well as the observation at low temperature of dislocations with (100) and (112)Burgers vectors.