Lattice dislocations consisting of pairs of 1/3[112] super-partials bounding superlattice intrinsic stacking faults were observed by transmission electron microscopy. They were found to react independently to antiphase boundary coupled 1/2[110] pairs in the commonly observed pure screw orientation. Boron was observed to have strong effects upon the population of boundary types, grain size, and grain growth. In addition, small amounts of B completely eliminate widely extended stacking faults. It was concluded that effects of B other than influencing boundary cohesion were important. Implications with regard to Kear-Wilsdorf type locking mechanisms and deformation behaviour were discussed.

Dislocation Structures and the Character of Superdislocations in Ni3Al Alloys. Kerans, R.J., Hirth, J.P., Clark, W.A.T.: Acta Metallurgica et Materialia, 1995, 43[1], 277-85