Advanced Magnetic Materials for Sensors, Power, and Multifunctional Applications: On-Demand Oral Presentations
Sponsored by: TMS Functional Materials Division, TMS: Magnetic Materials Committee
Program Organizers: Daniel Salazar, BCMaterials; Alex Leary, NASA Glenn Research Center; Eric Theisen, Energy & Environmental Research Center; Huseyin Ucar, California Polytechnic University,Pomona; Yongmei Jin, Michigan Technological University
Monday 8:00 AM
March 14, 2022
Room: Energy & Environment (including REWAS 2022 Symposia)
Location: On-Demand Room
Magnetization Measurements from Nanometer-sized Regions: Progress in Electron Holography: Yasukazu Murakami1; 1Kyushu University
Electron holography, which is a method related to transmission electron microscopy, can be a powerful tool for revealing the magnetic structures in a nanometer-scaled area. This method determines the phase shift in the incident electron wave that has traversed a thin-foil specimen. Because of the progress in the peripheral techniques in the previous 10 years (i.e., processing to reduce undesired phase information, methods of noise reduction, application of high-sensitive camera, etc.), the precision of electron holography has been improved significantly. We will discuss about several topics about recent electron holography observations, including (1) development/depression of the ferromagnetic spin order in planar defects (i.e., antiphase boundaries), (2) magnetic flux density measurements from narrow grain boundaries in sintered magnets, and (3) applications of information science and technologies for further improvement of sensitivity in electron holography.
Effect of Hot Band Annealing and Final Annealing Temperatures on the Texture, Grain Size and Magnetic Properties of 1.2 wt% Si Non-oriented Electrical Steel: Youliang He1; Mehdi Mehdi1; Tihe Zhou2; Chad Cathcart2; Peter Badgley2; Afsaneh Edrisy3; 1Canmetmaterials, Nrcan; 2Stelco Inc.; 3University of Windsor
A 1.2 wt% Si non-oriented electrical steel (NOES) was processed using conventional rolling-annealing routes. The hot-rolled steel was annealed at various temperatures from 850 to 1000 °C for 4 hours and cold rolled to a thickness of 0.5 mm. The steel was final annealed at temperatures varying from 700 to 850 °C for 24 hours. The textures and magnetic properties of the steel sheets were characterized by electron backscatter diffraction (EBSD) and Epstein frame techniques, respectively. It was found that hot band annealing at 850 °C for 4 hours followed by final annealing at 800 °C for 24 hours resulted in the lowest core loss (60 Hz, 1.5 T) of 3.59 W/Kg, which is 26% lower than the core loss obtained without hot band annealing (final annealing at 700 °C). Correlations among the magnetic properties, grain size and texture factor were evaluated for all the annealing conditions to discuss the effect of the annealing conditions on the magnetic properties.
Custom-designed Miniature-coil Winding/Wrapping Machine: Balraj Mani1; Bilal Adra1; Nuggehalli Ravindra1; 1New Jersey Institute of Technology
Magnetic field assisted assembly techniques are gaining acceptance as a novel concept in the intricate placement of devices on substrates at wafer-level. The research into such innovative techniques require creation of a uniform magnetic field to begin with. This will require a large array of milli-scale electromagnets needing a large number of miniature electromagnetic coils of uniform size. Such coils are required in varying lengths from 5.0mm to 25.0mm, core diameters ranging from 0.5mm to 2.0mm and wire sizes ranging from AWG 24 to 32. Dual-layer coils will double the magnetic field strength compared to mono-layer coils. In addition, dual-layer coils will result in a coil structure in which the leads will terminate at the same end of the coil. This talk will discuss the design of the Coil Winding/Wrapping Machine, its unique features, performance and the outcomes.
High Saturation Magnetization of FeCoN Bulk Martensite: Tomohiro Tabata1; Matahiro Komuro1; Yusuke Asari1; Shinya Tamura1; Shohei Terada1; Satoshi Sugimoto2; 1Hitachi, Ltd.; 2Tohoku University
Fe16N2 with ordered nitrogen martensite has been reported to have a high saturation magnetization (μ0MS) of 2.80 T. On the other hand, according to the Slater-Pauling rule, the addition of Co to Fe is known to increase μ0MS. Based on these findings, it is expected that the μ0MS can be enhanced by introducing nitrogen-based martensite into the Fe-Co system. In this study, we report the enhancement of μ0MS by bulk Fe-Co-N martensite synthesized by gas nitriding method. The μ0MS of the fabricated foils was evaluated using a vibrating sample magnetometer and showed a high value of 2.43 T (241 A·m2/kg), which is about 3% higher than that of the raw material. The formation of martensite on the foil surface was confirmed by X-ray diffraction measurement. Therefore, it is considered that the formation of Fe-Co-N martensite by gas nitriding was successfully achieved and thereby the μ0MS was enhanced.
Correlation of Microstructure and Hard Magnetic Properties in Ce-Fe-B Magnet: Xubo Liu1; Ikenna Nlebedim1; 1Ames Laboratory, CMI
Resource-rich and cost-effective Ce-Fe-B magnets suffered from a low coercivity (200-400 kA/m) due to a weak magnetic anisotropy field (Ha= 2.40 MA/m). In this work, we have studied the correlation between microstructure and coercivity in Ce-Fe-B magnet using a large-scale micromagnetic simulation. The distribution and the magnetic properties of the grain boundary phase (GBP) have the most critical effect on coercivity. The nucleation of magnetization reversal prefers at the surface of the Ce2Fe14B (2:14:1) grain neighboring with a soft magnetic GBP or that without GBP isolated it from other 2:14:1 grains. Additionally, the local misalignment of 2:14:1 grains reduces the coercivity and squareness of the magnetization hysteresis loop. Further, the fluctuation of magnetic anisotropy and the variation of grain size significantly impact the squareness. We will present tuning of the distribution and properties of GBP as an effective way for improving coercivity in Ce-Fe-B magnet.
Characterization of Black Box Medium Voltage, Medium Frequency, Transformers for High Power Converters: Richard Beddingfield1; Apoorv Agarwal1; Subhashish Bhattacharya1; 1North Carolina State University
High power, medium voltage, medium frequency, transformers (MVMFTX) are the principal component that enables solid-state transformer (SST) operation with galvanic isolation. As SST technologies mature, there are new suppliers of commercial MVMFTX prototypes. However, these commercial prototypes are seldom provided with construction details which are essential to understanding the transformer performance and behavior. Furthermore, these details may be protected intellectual property, making the MVMFTX a proverbial black box. Proper design and operation of SSTs need accurate models of the transformer to understand basic issues as losses, saturation, common-mode impedance. In this presentation, we will describe and show a sufficient characterization process with LCR meters and an MV characterization circuit to capture the small and large signal behavior of the MVMFTX. We will identify critical construction and material properties. Furthermore, the application relevant MVMFTX material characterization can validate of requested specifications and define critical operational bounds for MV SST performance.
Ordering and Its Effect on Magnetostrictive Behavior in Fe-Al Single Crystals: Travis Willhard1; Andrew Laroche1; Rahulkumar Sunil Singh1; Sivaraman Guruswamy1; 1University of Utah
Fe-Al alloys are of interest as high strength, ductile and low cost magnetostrictive alloys. This work examines how the nature of short range ordering (SRO) changes with thermal history in Fe-16.4 at.% Al single crystal and how this influences magnetostriction. [200]-, [220]- and [111-oriented single crystals with three different thermal histories were prepared: (a) as-grown condition from the vertical Bridgman growth process, (b) annealed at 1373 K after crystal growth, and (c) high temperature annealing (HTA) followed by low temperature anneal at 573 K. XRD examination was used to characterize the phases present and SRO. As-grown crystal sample and low temperature annealed samples show SRO that predominantly has B2 like local arrangements and a very small number of DO3-like arrangements. HTA sample showed SRO with only B2 like local arrangements. HTA samples showed lower of magnetostriction values compared to as-grown samples contrary to expectation and a detailed examination is underway.