Efficiency of collisional precipitate resolution

The morphology of a multi-phase structure under irradiation is determined by the counteraction of precipitate dissolution due to cascade mixing and re-precipitation due to freely migrating irradiation-induced point defects. A steady state boundary may occur when the precipitate volume change rates due to the two processes match each other. Such a boundary was observed for a Cu-Ni-Fe alloy. Consideration of the detection limit for precipitate dissolution focusses attention to the magnitude of the dissolution rate. A new method for determining dissolution rates by atom probe analysis is described. Measured data are compared with cascade mixing rates as determined in ion beam mixing experiments. 11 refs.; 3 figs. (author)