A new mechanism for ½<110> and ½<112> dislocation pinning in this material was considered. The mechanism was based upon the inability of ½<110> perfect dislocations and ½<112> super-dislocations to propagate through small  ordered domains in which the two -phase grains were related by an order relationship that was equivalent to a 120 rotation about <111>. At temperatures below which the 90 ordered domains could not be removed by diffusion, and the dislocations could not climb around obstacles, the ½<110> perfect dislocations or ½<112> super-dislocations were expected to be pinned at discrete pockets of ordered domain and give rise to ½<110> or ½<112> dislocation loops within the matrix.

B.J.Inkson: Scripta Materialia, 1996, 35[8], 967-71