Effects of Fe Content on Microstructure and Properties of Secondary Al-Si Alloys
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.
Fe contentsecondary Al-Si Alloysiron-rich phasemechanical property
万方数据
维普
