Effect of Sc and Er additions on superplastic ductilities in Al-Mg-Mn-Zr alloy  

作　　者：段雨露 钱健 肖丹 崔学敏 徐国富 

机构地区：[1]School of Materials Science and Engineering, Central South University, Changsha 410083, China [2]Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education (Central South University), Changsha 410083, China [3]State Key Laboratory of Powder Metallurgy (Central South University), Changsha 410083, China

出　　处：《Journal of Central South University》2016年第6期1283-1292,共10页中南大学学报（英文版）

基　　金：Project(2014M552149) supported by the China Postdoctoral Science Foundation;Project(CX2016B041) supported by the Hunan Provincial Innovation Foundation For Postgraduate,China;Project(CSUZC201614) supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China

摘　　要：The superplasticity of Al-6Mg-0.4Mn-0.25Sc-0.12Zr and Al-6Mg-0.4Mn-0.25Er-0.12Zr(mass fraction,%)alloys sheet was investigated,and the effect of Sc and Er was discussed.The results show that the superplastic ductilities of Al-Mg-Mn-Sc-Zr alloy was higher than that of Al-Mg-Mn-Er-Zr alloy at a wide temperature range of 400-540°C and high strain rate range of1.67×10-4-1.67×10-1 s-1.A maximum elongation 673%is obtained at 520°C and 1.67×10-3 s-1 in the Sc-containing alloy;while the Er-containing alloy only gets a maximum elongation 253%at 520°C and 1.67×10-3 s-1.Moreover,the average stress exponent of Sc-containing alloy is about 2.84,which is smaller than that of Er-containing alloy(3.64).Besides,the activation energies of the Sc-containing and Er-containing alloy are 84.8 k J/mol and 87.2 k J/mol,respectively.It is indicated that grain boundary sliding is the dominant mechanism during tensile deformation.According to microstructure examination,the better superplasticity of Sc-containing alloy may be attributed to the presence of Al3_(Sc,Zr)dispersoids,which can inhibit recrystallization and grain growth effectively.The superplasticity of Al-6Mg-0.4Mn-0.25Sc-0.12Zr and Al-6Mg-0.4Mn-0.25Er-0.12Zr （mass fraction, %） alloys sheet was investigated, and the effect of Sc and Er was discussed. The results show that the superplastic ductilities of Al-Mg-Mn-Sc-Zr alloy was higher than that of Al-Mg-Mn-Er-Zr alloy at a wide temperature range of 400？540 °C and high strain rate range of 1.67×10？4？1.67×10？1 s？1. A maximum elongation 673%is obtained at 520 °C and 1.67×10？3 s？1 in the Sc-containing alloy;while the Er-containing alloy only gets a maximum elongation 253%at 520 °C and 1.67×10？3 s？1. Moreover, the average stress exponent of Sc-containing alloy is about 2.84, which is smaller than that of Er-containing alloy （3.64）. Besides, the activation energies of the Sc-containing and Er-containing alloy are 84.8 kJ/mol and 87.2 kJ/mol, respectively. It is indicated that grain boundary sliding is the dominant mechanism during tensile deformation. According to microstructure examination, the better superplasticity of Sc-containing alloy may be attributed to the presence of Al3（Sc, Zr） dispersoids, which can inhibit recrystallization and grain growth effectively.

关 键 词：Al-Mg-Sc alloy Al-Mg-Er alloy SUPERPLASTICITY microstructure 

分 类 号：TG146.21[一般工业技术—材料科学与工程]