Ling Wang¹, Wei-Ying Chen², David Martin¹, Peter Baldo², Meimei Li², Brian Wirth¹, Steven Zinkle¹; ¹University of Tennessee, ²Argonne National Laboratory

The dose dependence for loss of precipitate coherency depends on the initial precipitate size and irradiation temperature due to their differences in atomic relaxation during absorption of point defects. The effect of chemical compositions on precipitate coherency loss in three dilute Cu-based binary alloys (1%Co, 1%Fe and 0.4%Cr) were investigated using in situ ion irradiations. These Cu alloys were thermally treated to produce coherent Co-, Fe- and Cr-rich precipitates with two different sink strengths (1013 and 1014/m2), respectively, and irradiated with 1 MeV Kr ions to dose of 0.2dpa at room temperature and post annealed to 500 °C. The lobe-lobe contrast under dynamical diffraction condition of different type coherent precipitates disappeared after irradiation to 0.01dpa. However, only Fe-rich precipitates show lobe-lobe contrast after post annealing to 450 °C. Molecular dynamics simulations were performed to understand the evolution of the Co-rich precipitate coherency loss for different sink strengths.