Formation and crystallization behavior of Fe-based amorphous precursors with pre-existing α-Fe nanoparticles-Structure and magnetic properties of high-Cu-content Fe-Si-B-Cu-Nb nanocrystalline alloys
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2021年第6期
论文作者：Yanhui Li Xingjie Jia Wei Zhang Yan Zhang Guoqiang Xie Zhiyong Qiu Junhua Luan Zengbao Jiao
文章页码：171 - 181
摘 要：Structure,crystallization behavior,and magnetic properties of as-quenched and annealed Fe81.3Si4 O13Cu1.7（Cu1.7） alloy ribbons and effects of Nb alloying have been studied.Three-dimensional atom probe and transmission electron microscopy analyses reveal that high-number-density Cu-clusters and Pre-existing Nano-sized a-Fe Particles（PN-a-Fe） are coexistence in the melt-spun Cu1.7 amorphous matrix,and the PN-α-Fe form by manners of one-direction adjoining and enveloping the Cu-clusters.Two-step crystallization behavior associated with growth of the PN-a-Fe and subsequent nucleation and growth of newly-formed α-Fe is found in the primary crystallization stage of the Cu1.7 alloy.The number densities of the Cu-clusters and PN-a-Fe in melt-spun Fe81.3-xSi4 B13Cu1.7Nbx alloys are gradually reduced with enriching of Nb,and a fully amorphous structure forms at 4 at.% Nb,although smaller Cu-clusters still exist.After annealing,2 at.% Nb coarsens the average size(Dα-Fe) of the α-Fe grains from 14.0 nm of the Nb-free alloy to 21.6 nm,and 4 at.% Nb refines the Dα-Fe to 8.9 nm.The mechanisms of the α-Fe nucleation and growth during quenching and annealing for the alloys with large quantities of PN-α-Fe as well as after Nb alloying have been discussed,and an annealing-induced oc-Fe growth mechanism in term of the barrier co-contributed by competitive growth among the PN-a-Fe and diffusion-suppression effect of Nb atoms has been proposed.A coercivity（HC） α Dα-Fe3 correlation has been found for the nanocrystalline alloys,and the permeability is inverse with the HC.
Yanhui Li1，Xingjie Jia1，Wei Zhang1，Yan Zhang2，Guoqiang Xie3，Zhiyong Qiu1，Junhua Luan4，Zengbao Jiao5
1. Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology2. Institute for Materials Research, Tohoku University3. School of Materials Science and Engineering, Harbin Institute of Technology(Shenzhen)4. Center for Advanced Structural Materials, Department of Materials Science and Engineering, City University of Hong Kong5. Department of Mechanical Engineering, The Hong Kong Polytechnic University
摘 要：Structure,crystallization behavior,and magnetic properties of as-quenched and annealed Fe81.3Si4 O13Cu1.7（Cu1.7） alloy ribbons and effects of Nb alloying have been studied.Three-dimensional atom probe and transmission electron microscopy analyses reveal that high-number-density Cu-clusters and Pre-existing Nano-sized a-Fe Particles（PN-a-Fe） are coexistence in the melt-spun Cu1.7 amorphous matrix,and the PN-α-Fe form by manners of one-direction adjoining and enveloping the Cu-clusters.Two-step crystallization behavior associated with growth of the PN-a-Fe and subsequent nucleation and growth of newly-formed α-Fe is found in the primary crystallization stage of the Cu1.7 alloy.The number densities of the Cu-clusters and PN-a-Fe in melt-spun Fe81.3-xSi4 B13Cu1.7Nbx alloys are gradually reduced with enriching of Nb,and a fully amorphous structure forms at 4 at.% Nb,although smaller Cu-clusters still exist.After annealing,2 at.% Nb coarsens the average size(Dα-Fe) of the α-Fe grains from 14.0 nm of the Nb-free alloy to 21.6 nm,and 4 at.% Nb refines the Dα-Fe to 8.9 nm.The mechanisms of the α-Fe nucleation and growth during quenching and annealing for the alloys with large quantities of PN-α-Fe as well as after Nb alloying have been discussed,and an annealing-induced oc-Fe growth mechanism in term of the barrier co-contributed by competitive growth among the PN-a-Fe and diffusion-suppression effect of Nb atoms has been proposed.A coercivity（HC） α Dα-Fe3 correlation has been found for the nanocrystalline alloys,and the permeability is inverse with the HC.
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