Effects of Squeeze Casting Specific Pressure on Microstructure and Mechanical Properties of Al-20Si Alloy for Automobile

Squeeze casting tests of Al-20Si alloy with different specific pressure were carried out.The effects of different specific pressure on the microstructure and properties of Al-20Si alloy were studied by OM, tensile test and fracture morphology observation.The results show that with the increase of squeeze casting specific pressure, the number and size of primary Si phase in Al-20Si alloy decrease gradually, and the roundness becomes higher and higher, the number of α-Al dendrite increases, the tensile strength of Al-20Si alloy increases first and then decreases, and the elongation increases gradually.When the specific pressure is 560 MPa, the maximum tensile strength of Al-20Si alloy is 165 MPa.When the specific pressure is 720 MPa, the maximum elongation of Al-20Si alloy reaches 6.1%.