Kim Cheol-Woo, Yoo Hyo-Sang, Jeon Jae-Yeol, Cho Jae-Ik, Hong Sung-Kil
Smart Mobility Materials and Components R&D Group, Korea Institute of Industrial Technology, 1110-9 Oryong-dong, Buk-gu, Gwangju, 61012, Republic of Korea.
School of Materials Science and Engineering, Chonnam National University, 61186, Republic of Korea.
J Nanosci Nanotechnol. 2021 Mar 1;21(3):1915-1919. doi: 10.1166/jnn.2021.18909.
Fe is considered as one of the most harmful trace elements among impurities in aluminum and its alloys due to its influence of the mechanical properties especially in elongation. It is therefore essential that the Fe content is controlled to improve quality and the toughness of aluminum alloy castings. Since demand for high strength aluminum alloy casting was significantly increased in electro materials and devices, automotive and airplane industries, it is necessary to characterize the effect of Fe and set the tolerable amount of Fe content in aluminum alloys. Al6061 alloys were prepared with compositions of 0.36, 0.45, 0.58, 0.65, 0.75, 0.81 and 0.91 wt.% Fe. Solidification characteristics were analyzed by CALPHAD (Pandat software) method. Mechanical properties such as hardness, tensile strength, elongation and fatigue strength were evaluated and compared with different Fe contents. AlFe₄ phase increased with increasing as Fe content, however, other phases, α-AlFeSi and Mg₂Si, showder a slight decrease. The higher the Fe content, the lower the electrical conductivity of the alloy due to the severe distortion of the Al matrix. As Fe content was more than specification of Al6061 alloy, 0.7 wt.%, the mechanical properties, especially, hardness and elongation were greatly influenced. The hardness is attributed to the poor densification and angular-shaped AlFe₄ phases unevenly distributed in the α-Al matrix.
由于铁对机械性能尤其是伸长率有影响，铁被认为是铝及其合金杂质中最有害的微量元素之一。因此，控制铁含量对于提高铝合金铸件的质量和韧性至关重要。由于电子材料与器件、汽车和航空工业对高强度铝合金铸件的需求显著增加，有必要表征铁的影响并设定铝合金中铁含量的容许量。制备了铁含量为0.36、0.45、0.58、0.65、0.75、0.81和0.91 wt.%的Al6061合金。通过CALPHAD（Pandat软件）方法分析凝固特性。对不同铁含量的硬度、抗拉强度、伸长率和疲劳强度等力学性能进行了评估和比较。随着铁含量增加，AlFe₄相增多，然而，其他相α-AlFeSi和Mg₂Si略有减少。由于铝基体严重畸变，铁含量越高，合金的电导率越低。当铁含量超过Al6061合金的规格0.7 wt.%时，力学性能，尤其是硬度和伸长率受到很大影响。硬度归因于致密化不良以及在α-Al基体中不均匀分布的角状AlFe₄相。
