FAULT ENERGIES IN ORDERED AND DISORDERED NI3FE

Ll//2 ordered alloys show an increase in the flow stress with increasing temperature which is correlated with the cross-slip of superlattice dislocations from left brace 111 right brace to left brace 100 right brace planes. Since the cross-slip behavior depends very much on the dissociation of the dislocations, it is the purpose of this work to determine the dissociation schemes and the fault energies of Ni//3Fe. Therefore the weak-beam method of transmission electron microscopy (TEM) is used to analyze the dissociation of the dislocations in disordered and ordered Ni//3Fe. From the splitting widths the fault energies can be deduced. In ordered Ni//3Fe sessile unit dislocations (b equals a/2 LT AN BR 110 RT AN BR ), which were introduced before ordering, and superlattice glide dislocations are studied.