[en] Transmission electron microscopy was used to compare the microstructure and particle distributions of two commercial oxide dispersion-strengthened copper alloys, GlidCop Al25 and MAGT 0.2. Measurements were made on specimens in their as-wrought condition, after thermal annealing for 1 h at 900 degrees C, and after 3 MeV Ar⁺ ion irradiation at 180 and 350 degrees C to damage levels of 20 to 30 displacements per atom (dpa). All of the annealed and ion-irradiated specimens were found to be resistant to recrystallization. In addition, void formation was not observed in any of the irradiated specimens. The GlidCop oxide particle geometry was transformed from triangular platelets to circular disks by the ion irradiation. the MAGT particle geometry consisted of circular disks and spheres before and after irradiation. The oxide particle edge length in the unirradiated GlidCop alloy was about 10 nm, whereas the mean diameter of the particles in the unirradiated MAGT alloy was about 6 nm. After irradiation, the mean particle diameter in both the MAGT and GlidCop alloys was about 6 nm