Effect of Cu content on the mechanical properties of an Al–Cu–Mg–Ag alloy

Abstract

The effect of Cu content on precipitation hardening, elevated temperature tensile strength and microstructure of an Al–Cu–Mg–Ag alloy was investigated. By increasing Cu content from 4 to 8 wt.%, the tensile strength increased from 434 to 559 MPa at room temperature, and from 141 to 228 MPa at 300°C, with only a slight drop in elongation. The high strength of the 8Cu alloy is attributed to the high density of fine Ω and θ′ precipitates and an additional Cu-containing intermetallic compound. Addition of Cu above its solubility in Al may induce excessive strengthening both at room and high temperatures.