Grain size-dependent Mg/Si ratio effect on the microstructure and mechanical/electrical properties of Al-Mg-Si-Sc alloys |
| |
| Affiliation: | 1. Center for High-Resolution Electron Microscopy, College of Materials Science & Engineering, Hunan University, Changsha, Hunan 410082, China;2. Hunan Province Key Laboratory for Spray Deposition Technology and Application, Hunan University, Changsha, Hunan 410082, China;1. Center for High-Resolution Electron Microscopy, College of Materials Science & Engineering, Hunan University, Changsha, Hunan 410082, China;2. Hunan Province Key Laboratory for Spray Deposition Technology and Application, Hunan University, Changsha, Hunan 410082, China;1. Faculty of Mechanical Engineering and Mechanics, Ningbo University, Ningbo, Zhejiang 315211, PR China;2. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, PR China;3. Science and Technology on Surface Physics and Chemistry Laboratory, Jiangyou, Sichuan 621907, PR China;1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, PR China;2. Department of Materials Physics and Chemistry, School of Materials Science and Engineering, Northeastern University, Shenyang 110819, PR China;3. Electric Power Research Institute of Liaoning Electric Power Co., Ltd., Liaoning Electric Power Co., Ltd., Shenyang 110006, PR China;1. Mechanical and Mechatronics Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L-3G1, Canada;2. Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, ON L8S-4L7, Canada;3. Department of Physics, and Centre for the Physics of Materials, McGill University, 3600 University Street, Montreal, QC H3A-2T8, Canada;4. Department of Mining and Materials Engineering, McGill University, 3610 University Street, Montreal, QC H3A-0C5, Canada;5. Novelis Global Research & Technology Center, 1950 Vaughn Road, Kennesaw, GA 30144, USA |
| |
| Abstract: | Al-Mg-Si-Sc alloys with different Mg/Si ratio (<1.73 in wt.% vs>1.73 in wt.%) and different grain size (coarse grains vs ultrafine grains) were prepared, which allowed to investigate the grain size-dependent Mg/Si ratio effect on the microstructural evolution and concomitantly on the hardness and electrical conductivity when subjected to aging at 200 °C. In the coarse-grained Al-Mg-Sc-Sc alloys, the β″ precipitation within the grain interior and also the precipitation hardening were highly dependent on the Mg/Si ratio, while the electrical conductivity was slightly affected by the Mg/Si ratio. A promoted β″ precipitation was found in the case of Si excess (Mg/Si ratio <1.73), much greater than in the case of Mg excess (Mg/Si ratio>1.73). While in the ultrafine-grained Al-Mg-Si-Sc alloys, the electrical conductivity rather than the hardness was more sensitive to the Mg/Si ratio. The alloy with Si excess displayed electrical conductivity much higher than its counterpart with Mg excess. This is rationalized by the grain boundary precipitation promoted by Si, which reduced the solute atoms and precipitates within the grain interior. Age softening was found in the ultrafine-grained alloy with Si excess, but the ultrafine-grained alloy with Mg excess held the hardness almost unchanged during the aging. The hardness-conductivity correlation is comprehensively discussed by considering the coupling effect of Mg/Si ratio and grain size. A strategy to simultaneously increase the hardness/strength and electrical conductivity is proposed for the Al-Mg-Si-Sc alloys, based on present understanding of the predominant factors on strengthening and conductivity, respectively. |
| |
| Keywords: | Al-Mg-Si-Sc Grain size effect Mg/Si ratio Precipitation Hardness/conductivity |
| 本文献已被 万方数据 ScienceDirect 等数据库收录！ |
|
