Creep Behavior and Microstructural Evolution of Al–Cu–Mg–Ag Alloys with Various High Cu Contents

The creep behavior and microstructural evolution of three Al–Cu–Mg–Ag alloys with Cu content around its solid solubility limit in Al (5.65 wt %) were investigated at 180–240 °C applied stress 150–300 MPa. resistance aged alloy, which is mainly determined by the number density ? phase, best for 6.00 % Cu, better 5.30 worst 5.65 Cu. After solid-solution treatment, lowest matrix alloy observed due to existence more residual phases. It results phase following aging poor resistance. Increasing temperature from 180 240 same (225 MPa), steady rate increases 225 times, apparently larger than that (26 times) increasing 300 MPa (180 °C). indicates coarsening should be serious stress. mechanism can attributed dislocation climb threshold