The additions of silicon, titanium and boron to the Al-4.97 wt. % Cu – 0.56 wt. % Ag based alloys (A201) were used to improve the castability, mechanical properties and microstructure. The four alloys: A201, A201+Si, A201+Ti+B and A201+Si+Ti+B were investigated in the as-cast, solution treated at 550C for ~ 20 hours and aged at 170C up to 32 days conditions. The effect of precipitation on the mechanical properties of the alloys were investigated by a combination of HRSEM, TEM and EDS. Addition of Si coarse the grain structure and changed the amount of the eutectic regions and affect the corrosion behavior. Additions of Ti and B refine the grain structure, produce the secondary phases which influenced the precipitation sequence then slowed down the age hardening process. Additions of Ti and B with Si affect the microstructure of A201 to contain more pores and also decrease the corrosion resistant.