Effect of Ta Solute Concentration on the Microstructural Evolution in Immiscible Cu-Ta Alloys

The immiscible Cu-Ta system has garnered recent interest due to observations of high strength and thermal stability attributed to the formation of Ta-enriched particles. This work investigated a metastable Cu-1 at.% Ta solid solution produced via mechanical alloying followed by subsequent consolidation into a bulk specimen using equal channel angular extrusion at 973 K (700°C). Microstructural characterization revealed a decreased number density of Ta clusters, but with an equivalent particle size compared to a previously studied Cu-10 at.% Ta alloy. Molecular dynamic stimulations were performed to understand the thermal evolution of the Ta clusters. The cluster size distributions generated from the simulations were in good agreement with the experimental microstructure.