挤压铸造比压对汽车用Al-20Si合金组织及力学性能的影响

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

摘要: 对Al-20Si合金进行了不同比压的挤压铸造试验，采用OM、拉伸试验、断口形貌观察研究了不同挤压铸造比压对Al-20Si合金组织与性能的影响。结果表明：随着挤压铸造比压的增加，Al-20Si合金中初生Si相的数量逐渐减少，尺寸逐渐减小，圆度越来越高，α-Al枝晶数量越来越多，Al-20Si合金的抗拉强度先升高后降低，伸长率逐渐升高。比压为560 MPa时，Al-20Si合金的抗拉强度达到最大值165 MPa。比压为720 MPa时，Al-20Si合金的伸长率达到最大值6.1%。

Abstract: 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%.