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Title: Microstructure and Hard Magnetic Properties of Sm1-xZrx(Fe,Co)11.3-yTi0.7By Ingots and Thick Melt-Spun Ribbons

Abstract

Permanent magnets made from Sm(Fe,Co)12-based compounds are being actively pursued through nanostructuring and powder metallurgy. This study was aimed at the development of hard magnetic properties in bulk as-cast alloys and in melt-spun alloys for very low wheel speeds. Slower solidification rates and alloying with Zr promote the tetragonal ThMn12-type crystal structure, whereas higher solidification rates and alloying with B replace the ThMn12 structure type with the TbCu7 structure type. When introduced simultaneously, Zr and B dramatically reduce the alloy solidification rates required for both the refinement of the 1:12 crystallites and their replacement with the 1:7 phase. In bulk arc-melted alloys, this allowed for a microstructure of separated 1:12 crystallites 1–3 μm in size, although, because of the ferromagnetic nature of a minority phase, the coercivity of these fine-grained alloys reached only 0.73 kOe. A moderately accelerated solidification further refined the 1:12 crystallites and increased the coercivity; a Sm0.7Zr0.4(Fe,Co)10.8Ti0.7B0.5 alloy exhibited a coercivity of 1.5 kOe and a maximum energy product of 3.4 MGOe when it was melt-spun into a 0.26-mm-thick ribbon. A more rapid solidification suppressed the 1:12 phase and after annealing at 800–850 °C, the alloys modified with Zr and B developed reasonably high coercivity and maximummore » energy product even when melt-spun at a wheel speed of 6 m/s. For the above-mentioned alloy, these values were 4.1 kOe and 7.8 MGOe, respectively. Further, a similarly processed very-Sm-lean Sm0.5Zr0.6(Fe,Co)10.6Ti0.7B0.7 alloy exhibited a remanence of 8.8 kG and an energy product of 7.4 MGOe.« less

Authors:
 [1];  [1]
  1. Univ. of Delaware, Newark, DE (United States)
Publication Date:
Research Org.:
Univ. of Delaware, Newark, DE (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1812306
Grant/Contract Number:  
FG02-90ER45413
Resource Type:
Accepted Manuscript
Journal Name:
IEEE Transactions on Magnetics
Additional Journal Information:
Conference: Intermag 2021, Lyon (Held Virtually) (France), 26-30 Apr 2021; Journal ID: ISSN 0018-9464
Publisher:
Institute of Electrical and Electronics Engineers. Magnetics Group
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; coercivity; melt-spinning; rare-earth magnets; ThMn12

Citation Formats

Gabay, Alexander M., and Hadjipanayis, George C.. Microstructure and Hard Magnetic Properties of Sm1-xZrx(Fe,Co)11.3-yTi0.7By Ingots and Thick Melt-Spun Ribbons. United States: N. p., 2021. Web. https://doi.org/10.1109/tmag.2021.3102513.
Gabay, Alexander M., & Hadjipanayis, George C.. Microstructure and Hard Magnetic Properties of Sm1-xZrx(Fe,Co)11.3-yTi0.7By Ingots and Thick Melt-Spun Ribbons. United States. https://doi.org/10.1109/tmag.2021.3102513
Gabay, Alexander M., and Hadjipanayis, George C.. Tue . "Microstructure and Hard Magnetic Properties of Sm1-xZrx(Fe,Co)11.3-yTi0.7By Ingots and Thick Melt-Spun Ribbons". United States. https://doi.org/10.1109/tmag.2021.3102513.
@article{osti_1812306,
title = {Microstructure and Hard Magnetic Properties of Sm1-xZrx(Fe,Co)11.3-yTi0.7By Ingots and Thick Melt-Spun Ribbons},
author = {Gabay, Alexander M. and Hadjipanayis, George C.},
abstractNote = {Permanent magnets made from Sm(Fe,Co)12-based compounds are being actively pursued through nanostructuring and powder metallurgy. This study was aimed at the development of hard magnetic properties in bulk as-cast alloys and in melt-spun alloys for very low wheel speeds. Slower solidification rates and alloying with Zr promote the tetragonal ThMn12-type crystal structure, whereas higher solidification rates and alloying with B replace the ThMn12 structure type with the TbCu7 structure type. When introduced simultaneously, Zr and B dramatically reduce the alloy solidification rates required for both the refinement of the 1:12 crystallites and their replacement with the 1:7 phase. In bulk arc-melted alloys, this allowed for a microstructure of separated 1:12 crystallites 1–3 μm in size, although, because of the ferromagnetic nature of a minority phase, the coercivity of these fine-grained alloys reached only 0.73 kOe. A moderately accelerated solidification further refined the 1:12 crystallites and increased the coercivity; a Sm0.7Zr0.4(Fe,Co)10.8Ti0.7B0.5 alloy exhibited a coercivity of 1.5 kOe and a maximum energy product of 3.4 MGOe when it was melt-spun into a 0.26-mm-thick ribbon. A more rapid solidification suppressed the 1:12 phase and after annealing at 800–850 °C, the alloys modified with Zr and B developed reasonably high coercivity and maximum energy product even when melt-spun at a wheel speed of 6 m/s. For the above-mentioned alloy, these values were 4.1 kOe and 7.8 MGOe, respectively. Further, a similarly processed very-Sm-lean Sm0.5Zr0.6(Fe,Co)10.6Ti0.7B0.7 alloy exhibited a remanence of 8.8 kG and an energy product of 7.4 MGOe.},
doi = {10.1109/tmag.2021.3102513},
journal = {IEEE Transactions on Magnetics},
number = ,
volume = ,
place = {United States},
year = {2021},
month = {8}
}

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This content will become publicly available on August 3, 2022
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