Strengthening of L12-ordered intermetallics by fine precipitation of coherent disordered phases

The minimum creep rates of polycrystalline L12-ordered intermetallics, Ni3(Al, Ti) and Co3Ti, decrease appreciably by the fine precipitation of disordered coherent phases. Transmission electron microscope observations of the interaction between dislocations and precipitates revealed that superdislocations produced by deformation tend to be strongly attracted and dissociate as they meet the disordered coherent precipitates because the anti-phase boundary energy in the matrix is high while that in the disordered precipitates is zero.