摘要
利用金相显微镜、X射线衍射仪、万能拉伸试验机等研究了Fe含量对再生铝硅合金组织和性能的影响,并对该合金中富铁相形态进行了定量分析.结果表明:当Fe含量从 0.796%增加到 1.301%时,合金组织中二次枝晶臂间距先减小再增大再减小;富铁相形貌的演变过程为紧密汉字状→汉字状+鱼骨状→汉字状+鱼骨状+针状→针状+汉字状→针状;合金中的富铁相面积分数逐渐上涨,富铁相长度不断增长,尤其当Fe含量从 1.022%上升到 1.301%,针状β-Fe相长度显著增长,平均长度最长可达 119.5 μm;β-Fe相的出现导致合金力学性能的显著下降,当Fe含量增至1.301%时,合金抗拉强度和伸长率相比 0.796%Fe时分别下降 26.26%和 52.58%.
Abstract
The effects of Fe content on the microstructure and properties of secondar Al-Si alloys were investigated by optical microscope,XRD and universal tensile testing machine,and quantitative analysis of the iron-rich phase morphology in the alloy.The results show that with the Fe content increasing from 0.796%to 1.301%,the secondary dendrite arm spacing in the alloy decreases,then increases and then decreases again.The morphology evolution sequence of iron-rich phase is as follows:compact Chinese script,Chinese script&fishbone-like,Chinese script&fishbone-like&needle-like,needle-like&Chinese script,needle-like;the area fraction of Fe-rich phase gradually increases and the length of Fe-rich phase grows,especially when the Fe content is in the range of 1.022%-1.301%,the length of needle-like β-Fe phase increases significantly,with the longest average length up to 119.5 μm;the appearance of β-Fe phase leads to a sharp decrease in the mechanical properties of the alloy.When Fe content increases to 1.301%,the tensile strength and elongation of the alloy decrease by 26.26%and 52.58%,respectively,compared with that of 0.796%Fe.
基金项目
国家自然科学基金资助项目(51864006)
国家自然科学基金资助项目(52165054)
广西自然科学基金资助项目(2018GXNSFAA281273)
广西自然科学基金资助项目(2020GXNSFAA159142)
维普
万方数据