Measuring strain fields and concentration gradients around Ni4Ti3 precipitates

Strain fields and concentration gradients around Ni4Ti3 precipitates in Ni-rich Ni–Ti have been quantified using advanced detection and analyzing tools of transmission electron microscopy. Strains up to 2% have been detected at distances up to 50 nm away from the precipitate–matrix interface while Ni-depletion down to 49.5 at.% Ni has been found in regions of the same dimensions. In all cases the values of the measured strain fields as well as concentration gradients perfectly compensate the related deformation and concentration changes estimated from the lattice parameter and composition of the precipitates.