电磁场频率对半连续铸造6013铝合金组织性能的影响

Effects of Electromagnetic Field Frequency on Microstructures and Properties of 6013 Aluminum Alloy Prepared by Semi-continuous Casting

采用低频电磁场半连续铸造工艺制备直径为?210 mm的6013铝合金铸锭,利用金相显微镜、扫描电镜、电子探针和拉伸试验机,研究了电磁场频率对铸锭显微组织与力学性能的影响。结果表明,施加低频电磁场可以细化铸锭中的α-Al晶粒,增加细小第二相数量,提高晶内元素含量,提高铸锭的拉伸力学性能。随着电磁场频率增加,α-Al晶粒逐渐从粗大的树枝晶转变为细小晶粒,晶粒大小和第二相分布逐渐均匀,铸锭边部的拉伸力学性能逐渐提高。与未施加低频电磁场的铸锭相比,当电磁场频率增加到40 Hz时,铸锭边部的抗拉强度、屈服强度和伸长率分别提高了9.62%、8.36%和62.89%。

6013 aluminium alloy ingot with 210 mm in diameter was prepared by low frequency electromagnetic field semi-continuous casting.The effects of electromagnetic field frequency on microstructures and mechanical properties of the ingot were investigated by optical microscope,scanning electron microscope,electron probe micro analysis and tensile testing machine.The results reveal that the low frequency electromagnetic field can refine theα-Al grains in the aluminum alloy ingot and increase the number of fine second phases as well as increasing the content of elements in the grain,so improving tensile properties of the ingot.With increasing in electromagnetic field frequency,theα-Al grains are converted gradually from coarse dendrites to fine grains,and the grain size and the second phase are gradually uniform distribution,so tensile properties of the ingot edge are improved gradually.Compared with the ingot without low frequency electromagnetic field,tensile strength,yield strength and elongation of the ingot edge are increased by 9.62%,8.36% and 62.89%,respectively,when the frequency of electromagnetic field is increased to 40 Hz.