The effect of annealing at 450$^\circ$C on the microstructure of a deformed alloy Cu-1.5Pd-3Ag (at.%)

Experiments were performed in order to study the surface and microstructure of the Cu-1.5Pd-3Ag alloy after deformation and annealing at a temperature of 450$^\circ$C for 48 hours with air cooling. It is shown that, after this treatment, silver is segregated on the alloy surface in the form of droplet-like particles that are well identified by atomic force microscopy and scanning electron microscopy. The particles lateral sizes are $\sim$0.1–0.5 $\mu$m, in some cases up to 1 $\mu$m. Experiment on X-ray photoelectron spectroscopy indicates that an oxide film with a thickness of no more than 10 nm is formed on the Cu-1.5Pd-3Ag alloy surface, which protects the sample from further oxidation over the its entire volume. According to X-ray diffraction analysis, it was found that, during annealing of the Cu-1.5Pd-3Ag alloy, fractions of two phases with different silver enrichment degrees are segregated: practically pure Ag and a compound close to Ag-31at.%Pd.