The microstructure

mechanical properties under different solid solution and aging conditions and internal defects of the squeeze casting A365.2 aluminum alloy engine mount bracket were investigated.The results reveal that microstructure of the heat-treated A356.2 alloy is composed mainly ofα-Al matrix

eutectic Si phase and Mg

2

Si phase with a grain size of about 148μm and the secondary dendrite spacing around 20μm.After solution aging treatment

part of the eutectic Si phase is dissolved into theα-Al matrix

and the other is distributed in the form of granular or spherical particle at theα-Al grain boundary.The solution time

aging temperature and aging time can affect the mechanical properties of A356.2.It is found that with solution at 535 ℃ for 6 hand water quenching for 8 min+ aging at 170℃for 6 h

the tensile strength

yield strength and elongation of the squeezing casting aluminum alloy bracket reach 340.5 MPa

274.5 MPa and 10%

respectively

meeting the mechanical properties standard required by the engine bracket.