Ion induced disordering and dissolution of Ni3Al precipitates

Abstract

The disordering of homogeneous Ni3Al and decomposed Ni(Al) alloys under irradiation with 300 keV Ni58 ions is studied at room temperature. In order to determine the development of the long-range order parameter, electron diffraction patterns are quantitatively evaluated taking into account dynamical diffraction effects. Although postulated by a recent model based on the thermal spike concept, no finite rest order is observed in the high-dose limit. The disordering rate of Ni3Al precipitates is much higher than that of homogeneous Ni3Al which is explained by the additional chemical dissolution of the particles due to ballistic mixing.