Tailoring nanoprecipitates for ultra-strong high-entropy alloys via machine learning and prestrain aging
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2021年第10期
论文作者：Tao Zheng Xiaobing Hu Feng He Qingfeng Wu Bin Han Chen Da Junjie Li Zhijun Wang Jincheng Wang Ji-jung Kai Zhenhai Xia C.T.Liu
文章页码：156 - 167
摘 要：The multi-principal-component concept of high-entropy alloys（HEAs） generates numerous new alloys.Among them,nanoscale precipitated HEAs have achieved superior mechanical properties and shown the potentials for structural applications.However,it is still a great challe nge to find the optimal alloy within the numerous candidates.Up to now,the reported nanoprecipitated HEAs are mainly designed by a trialand-error approach with the aid of phase diagram calculations,limiting the development of structural HEAs.In the current work,a novel method is proposed to accelerate the development of ultra-strong nanoprecipitated HEAs.With the guidance of physical metallurgy,the volume fraction of the required nanoprecipitates is designed from a machine learning of big data with thermodynamic foundation while the morphology of precipitates is kinetically tailored by prestrain aging.As a proof-of-principle study,an HEA with superior strength and ductility has been designed and systematically investigated.The newly developed γ’-strengthened HEA exhibits 1.31 GPa yield strength,1.65 GPa ultimate tensile strength,and 15% tensile elongation.Atom probe tomography and transmission electron microscope characterizations reveal the well-controlled high γ’ volume fraction（52%） and refined precipitate size（19 nm）.The refinement of nanoprecipitates originates from the accelerated nucleation of the γ’ phase by prestrain aging.A deeper understanding of the excellent mechanical properties is illustrated from the aspect of strengthening mecha nisms.Finally,the versatility of the current design strategy to other precipitation-hardened alloys is discussed.
Tao Zheng1，Xiaobing Hu1，Feng He1,2，Qingfeng Wu1，Bin Han2,3，Chen Da2，Junjie Li1，Zhijun Wang2，Jincheng Wang1，Ji-jung Kai2,4，Zhenhai Xia5，C.T.Liu4,6
1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University2. Center for Advanced Nuclear Safety and Sustainable Development, City University of Hong Kong3. Institute of Atomic and Molecular Science, Shaanxi University of Science and Technology4. Department of Material Science and Engineering, College of Science and Engineering, City University of Hong Kong5. Department of Materials Science and Engineering, University of North Texas6. Center for Advanced Structural Materials, Department of Mechanical Engineering, College of Science and Engineering, City University of Hong Kong
摘 要：The multi-principal-component concept of high-entropy alloys（HEAs） generates numerous new alloys.Among them,nanoscale precipitated HEAs have achieved superior mechanical properties and shown the potentials for structural applications.However,it is still a great challe nge to find the optimal alloy within the numerous candidates.Up to now,the reported nanoprecipitated HEAs are mainly designed by a trialand-error approach with the aid of phase diagram calculations,limiting the development of structural HEAs.In the current work,a novel method is proposed to accelerate the development of ultra-strong nanoprecipitated HEAs.With the guidance of physical metallurgy,the volume fraction of the required nanoprecipitates is designed from a machine learning of big data with thermodynamic foundation while the morphology of precipitates is kinetically tailored by prestrain aging.As a proof-of-principle study,an HEA with superior strength and ductility has been designed and systematically investigated.The newly developed γ’-strengthened HEA exhibits 1.31 GPa yield strength,1.65 GPa ultimate tensile strength,and 15% tensile elongation.Atom probe tomography and transmission electron microscope characterizations reveal the well-controlled high γ’ volume fraction（52%） and refined precipitate size（19 nm）.The refinement of nanoprecipitates originates from the accelerated nucleation of the γ’ phase by prestrain aging.A deeper understanding of the excellent mechanical properties is illustrated from the aspect of strengthening mecha nisms.Finally,the versatility of the current design strategy to other precipitation-hardened alloys is discussed.
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