ABSTRACTBased on studies of several binary trialuminides, it has been concluded that those with the L12 structure offer the best prospects for developing useful mechanical properties. Further, evaluation of a series of cubic ternary alloys produced by alloying Al3Ti with fourth period transition elements from Cr to Cu has shown that the mechanical properties and lattice parameters of the cubic alloys vary in a consistent manner with the location of the ternary alloying element in the periodic table. These structure/property relationships have been interpreted in terms of the number of d-shell electrons available for bonding. The Cr- and Mn-modified alloys have been shown to be the most attractive in terms of hightemperature structural applications. Finally, the work has resulted in a suggested mechanism for the D022 to Ll2 transformation on alloying.