TY - JOUR
T1 - 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
AU - Li, Yanhui
AU - Jia, Xingjie
AU - Zhang, Wei
AU - Zhang, Yan
AU - Xie, Guoqiang
AU - Qiu, Zhiyong
AU - Luan, Junhua
AU - Jiao, Zengbao
N1 - Funding Information:
The authors thank Xiangcheng Ren for conducting part of experiments. This work was financially supported by the National Natural Science Foundation of China (Nos. 51571047 , 51771039 , and 51871039 ); and the National Key Research and Development Program of China (No. 2017YFB0903903 ).
Publisher Copyright:
© 2020
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2021/2/28
Y1 - 2021/2/28
N2 - Structure, crystallization behavior, and magnetic properties of as-quenched and annealed Fe81.3Si4B13Cu1.7 (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 α-Fe Particles (PN-α-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-α-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-α-Fe in melt-spun Fe81.3−xSi4B13Cu1.7Nbx 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 α-Fe growth mechanism in term of the barrier co-contributed by competitive growth among the PN-α-Fe and diffusion-suppression effect of Nb atoms has been proposed. A coercivity (Hc) ∝ Dα-Fe3 correlation has been found for the nanocrystalline alloys, and the permeability is inverse with the Hc.
AB - Structure, crystallization behavior, and magnetic properties of as-quenched and annealed Fe81.3Si4B13Cu1.7 (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 α-Fe Particles (PN-α-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-α-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-α-Fe in melt-spun Fe81.3−xSi4B13Cu1.7Nbx 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 α-Fe growth mechanism in term of the barrier co-contributed by competitive growth among the PN-α-Fe and diffusion-suppression effect of Nb atoms has been proposed. A coercivity (Hc) ∝ Dα-Fe3 correlation has been found for the nanocrystalline alloys, and the permeability is inverse with the Hc.
KW - Crystallization behavior
KW - Cu-cluster
KW - Fe-based nanocrystalline alloy
KW - Pre-existing α-Fe nanoparticle
KW - Soft magnetic property
UR - http://www.scopus.com/inward/record.url?scp=85092383086&partnerID=8YFLogxK
U2 - 10.1016/j.jmst.2020.05.049
DO - 10.1016/j.jmst.2020.05.049
M3 - Journal article
AN - SCOPUS:85092383086
VL - 65
SP - 171
EP - 181
JO - Journal of Materials Science and Technology
JF - Journal of Materials Science and Technology
SN - 1005-0302
ER -