Effect of aging route on the precipitation behavior and thermal stability of Al–Cu–Mg–Ag alloy
Zhe Yu, He Li, Pengzhan Cai, Xiaoxiao Fu, Zongqiang Feng, Ling Zhang, Jinsan Wang, Namin Xiao
Abstract
In this study, the evolution of Ω plates during artificial aging and the effect of peak-aging treatment and over-aging treatment on the thermal stability of Al–Cu–Mg–Ag alloy were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was shown that the diameter distribution of Ω plates in the over-aged sample was narrower compared to the peak-aged one, which suppressed the Ostwald ripening in the over-aged sample. In addition, the Ω plates in the over-aged sample has a larger aspect ratio than that in the peak-aged sample, which makes it more likely for the soft impinge to inhibit the growth of the Ω plates. Quantitative analysis showed that after heat exposure, Ω plates in the over-aged sample contributed more to the yield strength compared to peak-aged sample. This study shows that better thermal stability can be obtained in exchange for a little loss of room temperature mechanical properties, improving the application potential of Al–Cu–Mg–Ag alloys.