Gen Res Inst Nonferrous Met;
State Key Lab Nonferrous Met & Proc;
Beijing 100088;
Peoples R China;
Jiangxi Univ Sci & Technol;
Engn Res Inst;
Ganzhou 341000;
Peoples R China;
Al-Cu-Mg-Ag alloys; precipitate size; synchrotron radiation; small angle X-ray scattering;