Al-5 Zn-2 Mg-1 Cu-0.2 Sc alloy was fabricated by rheo-squeeze casting. The effects of pouring temperature on the microstructure and mechanical properties of semi-solid slurry and rheo-squeeze casting alloy were investigated by tensile test

SEM and TEM. The results reveal that with the decrease of pouring temperature

the morphology of the primary α-Al phases in semi-solid slurry and rheo-squeeze casting alloy is gradually converted to the nearly equiaxed ones

and the second phase near the grain boundaries is more evenly distributed

with the average grain size decrease and the roundness increase.When the pouring temperature is 700 ℃

the size of the primary phase in the semi-solid slurry reaches about 35 μm with the average shape factor around 0.49

and the average grain size of the rheo-squeezecasting alloy is about 43 μm.The mechanical properties of rheo-squeeze casting alloy are enhanced with the decrease of pouring temperature. After 470 ℃×10 h+500 ℃×2 h solution treatment

most of the second phase is dissolved in the matrix. After 120 ℃×24 h aging treatment

the yield strength

tensile strength and elongation of Al-5 Zn-2 Mg-1 Cu-0.2 Sc alloy reach 539 MPa

612 MPa and 11%

respectively.