Achieving high strength and high ductility in precipitation-hardened alloys

A technique for producing high strength and high ductility in precipitation-hardened alloys at ambient temperatures, based on introduction of intermediate metastable phases into ultrafine-grained microstructures was investigated. The investigation was conducted using an aluminum-silver alloy containing 10.8 wt.% Ag. The precipitation of stable γ-phase particles onto the grain boundaries after aging for 10 h, was observed, with the particles having an average size range of ∼100-200 nm. The results show that sampler processed and aged with this technique, exhibits a stress-strain curve having a region of strain hardening, an extensive uniform strain, and high tensile ductility.