A study of dissociated antiphase boundaries in Ni₃Mo

The behaviour of non‐conservative antiphase boundaries in the intermetallic alloy Ni₃Mo has been examined by means of electron microscopy and electron diffraction. Particularly the new concept of “dissociated antiphase boundaries” has been worked out in detail. From structural considerations, a model for the splitting of antiphase boundaries has been proposed. The predictions for the fault planes, the displacement vector and the Burgers vector of the attached dislocation are completely confirmed by the observations. It was found that growth antiphase boundaries were roughly parallel to the (100) plane and that almost all antiphase boundaries possessed a displacement vector of 1/4 [102]. The Burgers vector of the dislocation present at the splitting centre was in agreement with the observed displacement vectors.