The tensile strength and elongation of hot extruded Al-Si-Cu-Mg alloy at room temperature can reach 296.6 MPa and 18%

respectively

showing significant improvement of mechanical properties of the alloy.Eutectic phase and secondary phase

including Al2Cu phase and Mg2Si phase

in the hot extruded Al-Si-Cu-Mg alloy can be converted from bulk particle or short rod into fine particles with more uniform distribution.After T6 treatment

the tensile strength of the alloy can reach 408 MPa with elongation more than 10%

which is attributed to the spheriodization of Si particle eliminating the stress concentration during tensile testing.