Fine-tuning the ductile-brittle transition temperature of Mg2Si intermetallic compound via Al doping
来源期刊：International Journal of Minerals Metallurgy and Materials2019年第4期
论文作者：Ao Li Xin-peng Zhao Hai-you Huang Yuan Ma Lei Gao Yan-jing Su Ping Qian
文章页码：507 - 515
摘 要：Brittleness is a dominant issue that restricts potential applications of Mg2Si intermetallic compounds（IMC）. In this paper, guided by first-principles calculations, we found that Al doping will enhance the ductility of Mg2Si. The underlying mechanism is that Al doping could reduce the electronic exchange effect between Mg and Si atoms, and increase the volume module/shear modulus ratio, both of which are beneficial to the deformation capability of Mg2Si. Experimental investigations were then carried out to verify the calculation results with Al doping contents ranging from Al-free to 10 wt%. Results showed that the obtained ductile-brittle transition temperature of the Mg2Si–Al alloy decreased and the corresponding ductility increased. Specifically, the ductile-brittle transition temperature could be reduced by about 100℃. When the content of Al reached 6 wt%, α-Al phase started to precipitate, and the ductile-brittle transition temperature of the alloy no longer decreased.
Ao Li1,2，Xin-peng Zhao1,2，Hai-you Huang1,2，Yuan Ma1,2，Lei Gao1,2，Yan-jing Su1,2,3，Ping Qian3,4
1. Institute for Advanced Materials and Technology,University of Science and Technology Beijing2. Corrosion and Protection Center,Key Laboratory for Environmental Fracture of Ministry of Education,University of Science and Technology Beijing3. Beijing Advanced Innovation Center for Materials Genome Engineering,University of Science and Technology Beijing4. Department of Physics,University of Science and Technology Beijing
摘 要：Brittleness is a dominant issue that restricts potential applications of Mg2Si intermetallic compounds（IMC）. In this paper, guided by first-principles calculations, we found that Al doping will enhance the ductility of Mg2Si. The underlying mechanism is that Al doping could reduce the electronic exchange effect between Mg and Si atoms, and increase the volume module/shear modulus ratio, both of which are beneficial to the deformation capability of Mg2Si. Experimental investigations were then carried out to verify the calculation results with Al doping contents ranging from Al-free to 10 wt%. Results showed that the obtained ductile-brittle transition temperature of the Mg2Si–Al alloy decreased and the corresponding ductility increased. Specifically, the ductile-brittle transition temperature could be reduced by about 100℃. When the content of Al reached 6 wt%, α-Al phase started to precipitate, and the ductile-brittle transition temperature of the alloy no longer decreased.
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