Effect of the elastic strain energy on the nucleation of Laves phases in α-iron base alloys

Abstract

The elastic strain energy of coherent clusters in Fe-Mo, Fe-Ti, Fc-Nb and Fe-Ta systems has been calculated as a function of their shapes and orientations using the Eshelbys method for anisotropic crystalline materials. The result is consistent with the formation of plate-shaped Laves phases in Fe-Nb, Fe-Ta and Fe-Ti systems and with that of spherical clusters, in Fe-Mo system, prior to the formation of plate-shaped Laves phase. The latter is believed to be formed due to the elastic interaction with the dislocations. The result also accurately predicts the {111}α habit plane of the Fe2Nb and the {001}α of the Fe2Ta Laves phases. The habit plane {011}α of the Fe2Ti Laves phase is not consistent with the calculation result for pure β Ti clusters. However, a strong segregation of Fe atoms into β Ti clusters can favor the formation of {011}α instead of {001}α habit planes. © 1995 Springer.