Effect of substitutional solid solution on dislocation nucleation in Fe ₃Al intermetallic alloys

Dislocation nucleation in solid solutions of body-centered-cubic intermetallic Fe ₃Al alloys was investigated by means of nanoindentation and measurement of the pop-in load of samples with different Cr content. It is clearly shown that the Cr solute element in the Fe ₃Al intermetallic alloy increases the pop-in load, i.e. shear stress, required for dislocation nucleation in a previously dislocation-free region. Changes in pop-in load track closely with changes in elastic properties, which can be interpreted within the framework of the universal features of metallic bonding as a change in the interatomic potential, as proposed by Rose et al.