Compressive yield-strength measurements and X-ray diffraction studies were made of the L12 intermetallic, and the behavior of the dislocations was determined by means of transmission electron microscopy. The long-range order parameter at 1273K was estimated to be 0.92, and the yield strength exhibited a decrease between 77K and room temperature but a slight increase at higher temperatures. During low-temperature deformation, a<110> super-dislocations glided on a{111} planes and dissociated into two a/3<112> super-partials which were separated by a superlattice intrinsic stacking fault. Its energy, as estimated from the dissociation distance, was 170mJ/m2 at 77K, 230mJ/m2 at 210K and 290mJ/m2 at 293K. The use of high-temperature in situ observations revealed that the width of the superlattice intrinsic stacking fault on {111} decreased with increasing temperature; until the super-dislocations began to dissociate, on {100} planes, into a/2<100> partials at 873K.

Electron Microscopic Analysis of Dislocation Structures in L12-Al3Sc Intermetallic Compound K.Fukunaga, Y.Miura: Journal of the Japan Institute of Metals, 1998, 62[4], 369-76