EFFECT OF ION IRRADIATION ON THE STRUCTURAL STABILITY OF DISPERSION-STRENGTHENED COPPER-ALLOYS

Transmission electron microscopy was used to compare the microstructur e and particle distributions of two commercial oxide dispersion-streng thened copper alloys, GlidCop Al25 and MAGT 0.2. Measurements were mad e 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 a nd 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 b e resistant to recrystallization. In addition, void formation was not observed in any of the irradiated specimens. The GlidCop oxide particl e geometry was transformed from triangular platelets to circular disks by the ion irradiation. The MAGT particle geometry consisted of circu lar disks and spheres before and after irradiation. The oxide particle edge length in the unirradiated GlidCop alloy was about 10 nm, wherea s the mean diameter of the particles in the unirradiated MAGT alloy wa s about 6 nm. After irradiation, the mean particle diameter in both th e MAGT and GlidCop alloys was about 6 nm.