Microstructure and mechanical properties of Al-Cu-Mg-Ag alloyed with Ce

The aged characteristics and microstructure of two Al-Cu-Mg-Ag alloys with and without Cc addition are investigated by TEM and mechanical properties test. The results show that trace Cc addition inhibits precipitating process and delays peak aging time. 0.25% Ce additions decrease both tensile strength and ductility. TEM observation shows that the morphology of Omega precipitate can be modified by the small addition of Ce. The trace Ce affects the microstructure by reducing the volume fraction of Omega precipitate. It can be concluded that the intensive interaction between Ce and Cu decreases the Cu atom concentration in alloy matrix and reduces the precipitated kinetics for Omega phase.