中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 29 No. 8 August 2019 |
（1. School of Mechanical Engineering, Guizhou University, Guiyang 550025, China;
2. School of Mechanical Engineering, Dongguan University of Technology, Dongguan 523808, China;
3. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China）
Abstract:The effect of Si content on the microstructures and mechanical properties of the heat-treated Al-6.5Cu-0.6Mn-0.5Fe alloy was investigated using image analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile testing. The results show that the mechanical properties of Al-6.5Cu-0.6Mn-0.5Fe alloys decrease slightly when the Si content is below 1.0%. This can be attributed to the comprehensive effect of microstructure evolution, including the increase of nano-sized α-Fe, the coarsened grain size, and an increase in Al2Cu content at the grain boundary. When the Si content is 1.5%, the mechanical properties of the Al-6.5Cu-0.6Mn-0.5Fe alloys decrease significantly, and this can be attributed to the agglomerated second intermetallics, which is resulted from the formation of excess Si particles.
Key words: Al-Cu alloys; iron-rich intermetallics; Si; tensile properties
