Direct observation of ion-irradiation-induced chemical mixing

Irradiation-induced dissolution of particles and mixing at heterogeneous interfaces in materials is of importance for ion beam processing and radiation materials sciences. Modeling has predicted dissolution of particles and homogenization at sharp chemical interfaces; imaging and depth profiling techniques have also been used to observe damage and mixing resulting from ion or neutron bombardment. Analytical scanning transmission electron microscopy has been used to directly observe the ion-irradiation induced elemental mixing and dissolution of ∼25–50 nm titanium oxycarbonitrides in a nanostructured ferritic alloy irradiated at 173 K. The magnitude of the mixed zone is consistent with radiation damage theory.

► Ion irradiation of nanostructured ferritic alloy at cryogenic temperature performed.
► Irradiation is seen to dissolve or broaden second-phase particles.
► Analytical electron microscopy is used to evaluate this mixing.
► Magnitude of mixing at interphase interfaces is compared to theory.