From dislocation cores to strength and work-hardening: a study of binary Ni3Al Original Research Article

A quantitative model for the peak temperature in work-hardening in L12 intermetallics is proposed. It is based on the competition between the exhaustion of mobile dislocations by the Kear Wilsdorf mechanism and the yielding of incomplete locks at high stress. The model is assessed by a set of experimental data measured in binary Ni3Al polycrystals of three different compositions. These include, in particular, the planar fault energies of the dislocation cores measured by weak-beam electron microscopy, combined with computer image simulations and macroscopic data about flow stress, work-hardening and mobile dislocation exhaustion rates. These parameters are measured as a function of alloy composition. The model also fits successfully data published for other L12 compounds.