Yoo Hyo-Sang, Kim Yong-Ho, Son Hyeon-Taek
Smart Mobility Materials and Components R&D Group, Korea Institute of Industrial Technology, 1110-9 Oryong-dong, Buk-gu, Gwangju, 61012, Republic of Korea.
J Nanosci Nanotechnol. 2021 Sep 1;21(9):4897-4901. doi: 10.1166/jnn.2021.19268.
In this study, changes in the microstructure, mechanical properties, and electrical conductivity of cast and extruded Al-Zn-Cu-Mg based alloys with the addition of Li (0, 0.5 and 1.0 wt.%) were investigated. The Al-Zn-Cu-Mg-Li alloys were cast and homogenized at 570 °C for 4 hours. The billets were hot extruded into rod that were 12 mm in diameter with a reduction ratio of 38:1 at 550 °C. As the amount of Li added increased from 0 to 1.0 wt.%, the average grain size of the extruded Al alloy increased from 259.2 to 383.0 m, and the high-angle grain boundaries (HGBs) fraction decreased from 64.0 to 52.1%. As the Li content increased from 0 to 1.0 wt.%, the elongation was not significantly different from 27.8 to 27.4% and the ultimate tensile strength (UTS) was improved from 146.7 to 160.6 MPa. As Li was added, spherical particles bonded to each other, forming an irregular particles. It is thought that these irregular particles contribute to the strength improvement.
在本研究中，研究了添加锂（0、0.5和1.0 wt.%）的铸造和挤压Al-Zn-Cu-Mg基合金的微观结构、力学性能和电导率的变化。将Al-Zn-Cu-Mg-Li合金铸造并在570℃下均匀化4小时。将坯料在550℃下热挤压成直径为12mm的棒材，挤压比为38:1。随着锂添加量从0增加到1.0 wt.%，挤压铝合金的平均晶粒尺寸从259.2μm增加到383.0μm，高角度晶界（HGBs）比例从64.0%下降到52.1%。随着锂含量从0增加到1.0 wt.%，伸长率从27.8%到27.4%没有显著差异，极限抗拉强度（UTS）从146.7MPa提高到160.6MPa。添加锂后，球形颗粒相互结合，形成不规则颗粒。据认为，这些不规则颗粒有助于强度的提高。
