The effects of eutectic Si agglomeration on mechanical properties and corrosion resistance of squeeze casting Al-Si-Mg alloy were investigated. The results reveal that the squeeze casting Al-Si-Mg alloy presents the eutectic Si agglomeration

which keeps after solid solution treatment and has adverse effects on the mechanical properties and corrosion resistance of the alloy. Corrosion test results reveal that after T6 heat treatment

the sample with eutectic Si aggregation has a corrosion potential of-820 mV and a corrosion current density of 1.91×10

-5

A/cm~2

and that with uniform eutectic Si distribution has a corrosion potential of-790 mV and a corrosion current density of 1.08×10

-5

A/cm~2. The corrosion cracks can be observed along the region where Si phase is aggregated. The sample with uniform eutectic Si distribution has better corrosion resistance. For mechanical properties

the agglomeration of eutectic Si has an adverse effect on the elongation of the alloy after T6 heat treatment. When the eutectic Si distribution is relatively uniform

the elongation and the tensile strength as well as the yield strength of the alloy reach up to 14.12%

332 MPa

and 271 MPa

respectively. When the eutectic Si phase is agglomerated and unevenly distributed

the elongation and the tensile strength as well as yield strength of the alloy reach 10.12%

324 MPa and 259 MPa

respectively.