Energy of Grain Boundaries of Different Type in fcc Solid Solutions, Ordered Alloys and Intermetallics with L12 Superstructure

The study of the triple junctions of the grain boundaries in some fcc solid solutions, ordered alloys and intermetallics with L12 has been carried out using the optical metallography and TEM methods. Two-types of the triple junctions were found in the alloys investigated (1), consisting of the boundaries of the random (RT), and (2), consisting of the RT boundary and the special boundaries (ST). The relative values of the RT and ST boundary energy were determined on the basis of the measurements of the angles between the grain boundary planes. It has been shown that the energy of ST boundaries increases with the increase of the stacking fault (SF) energy. The energy of the RT boundaries does not depend on the SF energy.