The relation between the defect hardening and substitutional solid solution hardening in an intermetallic compound Ni3Al

The relation between the defect hardening resulting from the deviation of composition and the exclusive substitutional solution hardening in the intermetallic compound Ni3Al is investigated by comparing the variation of lattice parameter and shear modulus with the change of compressive yield stress. In either case, the hardening rates are expressed by Fleischer's parameter in consideration of both effects, namely the elastic interaction between dislocations and solute atoms. Consequently, it is concluded that the defect hardening in Ni3Al is to be regarded as a sort of a substitutional solution hardening, and both hardening effects are controlled by the same mechanism.