Effects of hot extrusion parameters on mechanical properties and microstructure of the 7055 alloy were investigated by tensile testing and microstructural observation

and they are compared with those of as-cast ones.The results reveal that microstructure and mechanical properties of the hot extruded 7055 aluminum alloy are obviously superior to those of as-cast ones.Meanwhile

with increasing in specific pressure

grain size in the microstructure of the alloy is increasingly refined

and tensile strength is gradually improved.With extrusion casting at 730℃ and 75MPa

the grain size in the alloy after T6 heat treatment is refined obviously with tensile strength of 681.4MPa and elongation of 7.14%.