Microstructure and properties of Al-2Mg-0.5Mn alloy with narrow crystallization temperature range realized by adding trace elements
(1. School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China;
2. Guizhou Aerospace Xinli Technology Co., Ltd., Guizhou 563000, China;
3. Manufacturing Center, CRRC Times Electric Co., Ltd., Zhuzhou 412001, China;
4. Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China;
5. Key Laboratory of Precious Metals Analysis and Exploration Technology of Ministry of Natural Resources, Zhengzhou 450012, China)
2. Guizhou Aerospace Xinli Technology Co., Ltd., Guizhou 563000, China;
3. Manufacturing Center, CRRC Times Electric Co., Ltd., Zhuzhou 412001, China;
4. Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China;
5. Key Laboratory of Precious Metals Analysis and Exploration Technology of Ministry of Natural Resources, Zhengzhou 450012, China)
Abstract: The wide crystallization temperature range of Al-Mg alloys is a key factor for the surface defect formation during continuous casting and rolling process. To reduce the crystallization temperature range of the alloy, the influences of trace Zn, Si, Zr and Ti elements on the microstructure and properties of Al-2Mg-0.5Mn alloy were investigated. The X-ray photoelectron spectroscopy, atomic force microscopy, scanning and transmission electron microscopy were used for microstructural characterization. The Ti and Zr additions could refine the grain size and improve the strength of the Al-Mg-Mn alloy by forming Al3Ti and Al3Zr in the alloy, while the crystallization temperature ranges of these alloys were wider. It was revealed that Zn and Si additions could form new secondary phases with Mg in the alloy, thus reducing the actual Mg content during later eutectic solidification process. Therefore, the crystallization temperature range of Al-2Mg-0.5Mn-0.2Zn-0.2Si alloy was narrower than that of Al-2Mg-0.5Mn alloy. The mechanical properties and corrosion resistance of Al-2Mg-0.5Mn alloy were also improved by the additions of Zn and Si.
Key words: Al-Mg alloy; continuous casting and rolling; mechanical properties; corrosion behavior; crystallization temperature range