Effects of Sc and Zr microalloying additions on the microstructure and mechanical properties of new Al-Zn-Mg alloys

详细信息	查看全文 | 推荐本文 |

• 作者：Ying Deng^a ; ^{csudengying@163.com} ; Zhimin Yin^a ; Kai Zhao^a ; Jiaqi Duan^a ; Zhenbo He^b
• 关键词：Aluminum alloys ; Precipitation ; Mechanical properties ; Microstructure ; Electron microscopy
• 刊名：Journal of Alloys and Compounds
• 出版年：2012
• 期刊代码：45_09258388
• 类别：ms
• 出版时间：25 July, 2012
• 卷：530
• 期：Complete
• 页码：71-80
• 文件大小：3036 K

摘要

Effects of Sc and Zr microalloying additions on the microstructure and mechanical properties of new Al-Zn-Mg alloys alloyed with a small amount of copper were investigated comparatively by tensile tests and microscopy methods. Compared with the strength of peak-aged Al-Zn-Mg alloy, the yield strength increased by 66 MPa after adding 0.10 wt.%Sc and 0.10 wt.%Zr, and improved by 96 MPa after adding 0.25 wt.%Sc and 0.10 wt.%Zr, respectively. Introduction of 0.10 wt.%Zr to Al-Zn-Mg alloy, the grain refinement effect of scandium did not occur by adding only 0.10 wt.%Sc, but appeared with an increase in scandium content to 0.25 wt.%. In the presence of 0.10 wt.%Zr, antirecrystallized effect of scandium appeared at 0.10 wt.%scandium concentration, and enhanced with an increase in the content of scandium. Main aging precipitates were two kinds of GP zones in under-aged alloys, and 畏鈥?phases in peak-aged alloys, respectively. Small additions of Sc and Zr did not retard or suppress the formation of aging precipitates in Al-Zn-Mg-Sc-Zr alloys. The strengthening effect from aging precipitates was much stronger than from Sc and Zr microalloying additions in Al-Zn-Mg-Sc-Zr alloys. In addition, the most important strengthening mechanisms of Sc and Zr microalloying in aged Al-Zn-Mg alloys was Orowan strengthening of secondary Al₃(Sc, Zr) particles.