[en] The damage produced by room temperature 100 keV Ar⁺ ion bombardment of two ordered alloys Fe-40 at.% Al and Fe-48 at.% Co-2 at.% V has been investigated by transmission electron microscopy. In the Fe-40 at.% Al alloy, the high stability of the ordered phase is confirmed for doses up to about 2 x 10¹⁶ ions/cm² (approx. equal to38 dpa). In contrast, in the Fe-Co-2V alloy, after an increase in size and density of the damaged regions, a significant decrease in the long range degree of order occurs at a fluence of about 10¹⁵ ions/cm², followed by complete disordering at 10¹⁶ ions/cm². During post-irradiation annealing experiments, the evolution and recovery of the damage does not occur significantly before 700 K. (orig.)