Advanced Magnetic Materials for Energy and Power Conversion Applications: Structures and Modelling of Soft Magnetic Materials
Sponsored by: TMS Functional Materials Division, TMS: Magnetic Materials Committee
Program Organizers: Daniel Salazar, BCMaterials; Alex Leary, NASA Glenn Research Center; Markus Chmielus, University of Pittsburgh; Ryan Ott, Ames Laboratory; Arcady Zhukov, University of the Basque Country
Wednesday 8:30 AM
February 26, 2020
Room: Del Mar
Location: Marriott Marquis Hotel
Session Chair: Hunter Henderson, Oak Ridge National Laboratory; Michael McHenry, Carnegie Mellon University
8:30 AM
Characterization of Surface Oxidation and Multi-phase Nanocrystallization in Soft Magnetic FeNi-based Metal Amorphous Nanocomposite Alloys: Paul Ohodnicki1; Kevin Byerly2; John Baltrus2; Ruishu Wright2; James Egbu2; Natan Aronhime3; Yuval Krimer3; Michael McHenry3; Elizabeth Kautz4; Arun Devaraj4; 1National Energy Technology Laboratory (presently at University of Pittsburgh); 2National Energy Technology Laboratory; 3Carnegie Mellon University; 4Pacific Northwest National Laboratory
Recent work has demonstrated significant improvements in mechanical properties of emergent high performing Co-rich and FeNi-based soft magnetic metal amorphous nanocomposite (MANC) alloys comprised of close packed (e.g. fcc) nanocrystals embedded within an amorphous matrix. Optimized FeNi-based alloys show high saturation induction and permeability as well as enhanced ductility, making them attractive for post-processing operations such as stamping of laminations for high-speed rotating electrical machinery. Formation of an adherent surface oxide layer is also believed to provide the necessary inter-laminate electrical insulation required to mitigate eddy current losses without the need for additional coatings or surface treatments. In this work, we present characterization of MANC alloys via complementary electron microscopy, atom probe tomography, and x-ray photoelectron spectroscopy. With this multimodal approach, we explore the detailed nature of the surface oxidation layer as well as the composition and structure of nanocrystals that form within the bulk during for optimized annealing treatments.
8:50 AM
Preparation of Fe-NC Soft Magnetic Material (Minnealloy) in Bulk Form with High Saturation Magnetization, Low Coercivity, and High Electrical Resistivity: Guannan Guo1; Jinming Liu1; Bin Ma1; Jian-Ping Wang1; 1University of Minnesota
Minnealloy had been put forward as a candidate materials for the new soft magnetic materials in the application in electronic field because of its high saturation magnetization, low anisotropic energy and high electrical resistivity. We proposed a new method to synthesis the Minnealloy via preparing Fe-C melt spun as precursor for low temperature nitriding to improve the uniformity of the chemical composition and microstructure. The introduction of carbon into the iron as raw materials can form Fe16C2 which has a negative magneto crystalline anisotropy compared with the Fe16N2, while still holding the high Ms. Fe16N2, Fe16C2 or Fe16(CN) could be found either in the same grain or co-exist with each other as separate grains. Meanwhile, the electrical resistance is greatly improved compared with pure iron or low carbon steel, which makes this material as a good candidate for electronic applications.
9:10 AM
Structure and Magnetic Properties of Novel High-magnetization Fe-Mn Powders Synthesized by Hydrogen Reduction of Nanoferrites: Tatsuya Kon1; Nobuyoshi Imaoka1; Kimihiro Ozaki1; 1National Institute of Advanced Industrial Science and Technology (AIST)
We have previously reported a study of novel Fe-Mn powders doped with 0.1–0.2 at% manganese prepared by the reduction of (Fe,Mn)3O4 nanopowders using hydrogen gas. We detected the presence of manganese in bcc iron phase in the Fe-Mn powders using X-ray absorption fine structure spectroscopy (XAFS). The Fe-Mn powders exhibited coercivity values ranging between 0.1–1 Oe. The saturation magnetization of the Fe-Mn powders was comparable with that of bulk pure iron, i.e., 218 emu/g. The presence of manganese in bcc iron phase should normally reduce the magnetization and increase coercivity. We discuss the relationship between the magnetic properties and structure of the Fe-Mn powders investigated via detailed magnetization measurements, analysis using Mössbauer spectroscopy, transmission electron microscopy and XAFS.
9:30 AM
Tunable Magnetic Properties in High-entropy FeCoNiAlxSix (0.2 < x < 0.5) Alloys: Kathem Bazzi1; Ramasis Goswami2; Tanjore Jayaraman1; 1University of Michigan-Dearborn; 2Naval Research Laboratory, US
High-entropy FeCoNiAlxSix alloys exhibit decent soft-magnetic and electromagnetic properties. We present the tunability of the soft-magnetic properties facilitated by the presence of metastable f.c.c. phase, instead of the stable f.c.c and b.c.c. phases, in the high-entropy alloys. The mechanically alloyed FeCoNiAl0.375Si0.375 resulted in the formation of a single-phase—metastable f.c.c.—alloy. At ambient temperature, the specific magnetization (σS) and coercivity (HC) of the as-prepared alloy was ~91 Am2/kg and ~5 kA/m, respectively. The magnetic characterization from 60 K to 900 K showed a steady decrease in MS, but the HC initially decreased and subsequently increased. The metastable phase was stable up to ~800 K and after that dissociated. Thermal-treatment improved the soft-magnetic properties while retaining the nanocrystallinity. While fabrication by equilibrium processing facilitates the formation of two stable phases—b.c.c. and f.c.c., mechanical alloying promotes the formation of metastable f.c.c. phase having relatively superior soft-magnetic properties and good thermal stability.
9:50 AM Break
10:05 AM
Prediction of Good Glass Forming Ability in Amorphous Soft Magnetic Alloys by Thermocalc Simulation and Experimental Validation: Yuval Krimer1; Natan Aronhime2; Paul Ohodnicki3; Michael McHenry1; 1Carnegie Mellon University; 2Carpenter Technologies; 3National Energy Technology Laboratory
Optimization of glass forming ability (GFA) in metal amorphous nanocomposites (MANCs) has potential to allow improvements in soft magnetic properties and enable hot stamping motor laminates. Thermocalc software was used to simulate liquidus and solidification ranges of (Fe70Ni30)80(B-Si-Nb)20 alloys, while varying glass former concentrations, to identify compositions with good GFA. A region with excellent GFA was identified at 14-18% B and 0-7% Si with the balance Nb, showing minima in liquidus and solidification range. GFA was ranked using differential scanning calorimetry (DSC), using GFA parameters Trg, ΔTxg, and γm. DSC results show that the simulation accurately predicts liquidus temperature, and regions of good GFA correspond to predicted minima in liquidus and solidification range. DSC results show that many alloys display a temperature range between glass transition temperature (Tg) and crystallization temperature (Tx), as high as 41°C, indicating that they may be hot formed and stamped into laminates.
10:25 AM
Electronic Structure of Nano-crystalline and Amorphous Soft Magnetic Materials: A Computational Methodology: Minyeong Choi1; Yang-Ki Hong1; Hoyun Won1; Woncheol Lee2; Seok Bae3; Dong-Hyeok Choi3; Seong-Gon Kim4; 1The University of Alabama; 2Samsung Electro-Mechanics; 3LG Innotek; 4Mississippi State University
Wide bandgap semiconductor devices are now available for advanced power electronics and motor controller and operational even at high-temperature, -switching speed, and -rotation. Accordingly, high magnetization soft magnetic materials are ubiquitous to achieve a high power density of transformer and inductor, thereby, high-efficiency electrical machines. The soft magnetic materials need the saturation magnetization (Ms) higher than 1.9 T and saturation magnetostriction (λ) of about 10-7. Both nanocrystalline and amorphous soft magnetic materials potentially meet such high Ms and low λ if the discovery of new chemical composition and materials processing continues. Therefore, we have calculated electronic structures of nanocrystalline Fe-Cu-Si-B and amorphous Fe-P-C soft magnetic materials using first-principles calculations based on the density functional theory (DFT) to obtain magnetic moments. In this paper, we will introduce the first-principles calculation methodology and report the calculated magnetic moments. This work was supported in part by the NSF IIP under grant No. 1650564.
10:45 AM
Thermal stability, Crystallization and Magnetic Properties of High Induction Metallic Ribbons Fe67Co20B13: Przemyslaw Zackiewicz1; Lukasz Hawelek1; Patryk Wlodarczyk1; Marek Hreczka1; Magdalena Steczkowska-Kempka1; Aleksandra Kolano-Burian1; 1Lukasiewicz Research Network - Insitute of Non-Ferrous Metals
In the field of new nanocrystalline, magnetically soft materials, one of the key roles plays the possibility of obtaining materials with the highest possible saturation magnetization. New materials are prepared using new technique of ultra-rapid annealing. High heating rate of 150-200 K/s. This process allows to obtain high saturation magnetization and low coercion field. The high induction metallic glass ribbons obtained via melt spinning technique with the chemical formula Fe67Co20B13 were investigated. Thermal stability, crystallization and magnetic properties like complex permeability, magnetic saturation and coercivity were studied. Thermal properties: solidus-liquidus curves, the crystallization temperatures and kinetics of the crystallization process were analysed by applying DSC calorimetry. For the samples in the form of toroidal cores, the B(H) dependence were analysed. The X-ray diffraction was used to analyse the crystalline structure evolution. Complex permeability were measured in the function of frequency range up to 110 MHz.
11:05 AM
Production of Strips of Low-loss Soft Magnetic Alloys by Cutting Processes: Brhayan Puentes1; James Mann2; Srinivasan Chandrasekar1; Kevin Trumble1; 1Purdue University; 2University of West Florida
Sheet production of soft magnetic alloys has been traditionally done by rolling due to its cost advantage compared to other methods. However, rolling introduces workability issues to the production of high-Si iron alloys. These workability issues prevent the low-cost production of sheets with outstanding soft magnetic properties, such as sheets of Fe-6.5Si wt%. Hybrid Cutting Extrusion (HCE) and Free Cutting (FC) present a new alternative for production of sheets of low-loss soft magnetic materials. The combination of a localized deformation zone, large plastic strains, high hydrostatic pressures, and high temperatures enhances the workability, thus suppressing the deformation mechanisms that lead to cracking in rolling. For this study, thin strips of Fe-4Si, Fe-6.5Si, Fe-3Si-3Al, and Fe-4Si-4Cr alloys were produced using HCE and FC. Characterization shows quality of the strips in terms of surface roughness, microstructure control and properties.
11:25 AM
Low Temperature Synthesis of Superparamagnetic Fe3O4 Morphologies Tuned Using Oleic Acid as Crystal Growth Modifier: Stanley Omorogbe1; Aireguamen Aigbodion1; Hilary Ifijen1; Nosa Ogbeide-Ihama2; Aline Simo3; Esther Ikhuoria4; 1Rubber Research Institute of Nigeria; 2Guinness Nigeria PLC ; 3iThemba Labs; 4University of Benin
Several strategies have been established for the synthesis of magnetic nanoparticles with tunable sizes, morphologies and magnetic properties. Most of these reports are based on synthesis of magnetic nanoparticles that involve use of environmentally malignant organic solvents and high temperature conditions. Here we present a facile, rapid, low temperature approach to synthesize crystalline Fe3O4 mesostructures with high magnetic properties via a microwave-assisted sonochemical method and studied the effects of conventional crystal growth modifiers: oleic acid (OA) in the evolution of Fe3O4 morphology. We observed that the TEM investigations for OA as crystal growth modifier resulted in primary nanocrystals of hexagonal prism like morphologies. The as-synthesized Fe3O4 exhibit superparamagnetic properties with high saturation magnetization and have no residual magnetism. Further, the cytotoxicity analysis of as-synthesized samples on H9c2 cells revealed that the samples were safe to cells at higher concentrations.