Quantifying the Effects of Grain Refiners Al-Ti-B and La on the Microstructure and Mechanical Properties of W319 Alloy
Xinxiu Liu,
Bing Wang,
Quan Li,
Junsheng Wang,
Chi Zhang,
Chengpeng Xue,
Xinghai Yang,
Guangyuan Tian,
Xiaoguang Liu,
Hongqun Tang
Affiliations
Xinxiu Liu
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
Bing Wang
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
Quan Li
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
Junsheng Wang
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
Chi Zhang
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
Chengpeng Xue
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
Xinghai Yang
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
Guangyuan Tian
School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China
Xiaoguang Liu
School of Materials Science and Engineering, University of Science & Technology Beijing, Beijing 100083, China
Hongqun Tang
Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Materials, Center of Ecological Collaborative Innovation for Aluminium Industry in Guangxi, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
It is well known that the microstructure distribution in recycled Al-Si alloys has a large impact on the final mechanical properties. In this study, the microstructure, including Fe-rich intermetallics and microporosity, was quantitatively adjusted using multi-scale characterization with microalloying rare earth elements and traditional grain refiners as the objects of study. It was found that the addition of Al-Ti-B to W319 recycled aluminum alloy reduces the microstructure size and Fe-rich intermetallics, while the addition of La facilitates the transformation of harmful β-Fe into less harmful particles and the densification of coarse eutectic Si, promoting the refining effects on the microstructure additionally. Therefore, the RE and Al-Ti-B master alloy could be a potential new grain refining agent, especially for Al-cast alloys when the ductility is critical for designing. The improvement in elongation far exceeds the original level, up to 69.6%, while maintaining the same level of strength or even better. At the same time, the excessive addition of La may lead to the depletion of Cu and Ti elements during heat treatment, degrading ductility and strength.
