Advances in Magnetic Materials: Poster Session
Sponsored by: TMS Functional Materials Division, TMS: Magnetic Materials Committee
Program Organizers: Jose Maria Porro, BCMaterials; Huseyin Ucar, California Polytechnic University,Pomona; Patrick Shamberger, Texas A&M University; Min Zou, Lab Magnetics, A Quadrant Company; Gaoyuan Ouyang, Ames Laboratory; Alex Leary, NASA Glenn Research Center
Monday 5:30 PM
March 20, 2023
Room: Exhibit Hall G
Location: SDCC
Session Chair: Patrick Shamberger, Texas A&M University
D-15: Effects of Machining and Electroplating on Magnetic Properties of Small Sintered NdFeB Magnets: Min Zou1; Jinghui Di2; Abby Shen3; Michelle Qian4; Hui Meng5; Qifeng Wei5; Christina Chen4; 1Lab Magnetics, A Quadrant Company; 2Hangzhou Magmax Technology Co., Ltd.; 3Quadrant Solutions Inc.; 4Quadrant International Inc.; 5Hangzhou Foresee Group Holding Co., Ltd.
Sintered NdFeB magnets with one or more of their dimensions less than 5 mm or even 1 mm are now widely used when high performance, low cost, and limit in space and weight are simultaneously demanded, for example in mobile phones, tablets, and laptop computers. These small sized magnets are commonly machined from as-sintered blocks, and then coated with anti-corrosion materials by electroplating. Machining and surface treatment prior to electroplating potentially risk magnetic properties due to damaged surface grains and oxygen/humidity exposure. In this presentation, the effects of machining and electroplating conditions on the magnetic properties of several grades of NdFeB magnets with their dimensions ranging from a few millimeters to less than 1 mm will be illustrated. The approaches of mitigating the risk of the magnetic property degradation during machining and electroplating process will be discussed.
D-16: Investigating Irradiated Superconducting Magnet Insulation Materials for Particle Accelerators and Other High-dose Environments: Christopher Reis1; 1University of California, Berkeley
Insulating materials are utilized broadly in different fields of research, including the instrument and control cables of nuclear reactors and superconducting magnets in particle accelerators for High-Energy Physics and Fusion research. Understanding how these resin systems are affected by high-radiation environments is therefore crucial. Since CTD-101K is known for being plagued with cracking and toughness issues at cryogenic temperatures, a major focus of this study was testing alternative resins with higher cryogenic toughness. In this study, industry-standard CTD-101K was cross-examined with the National High-Magnetic Field Laboratory’s (NHMFL) mix 61 and the epoxy developed for ATLAS End Cap Toroid (ATLAS-ECT). These materials underwent gamma irradiation at 25, 50, 75 and 100 MGY and then characterized by alterations to their physical structure (mass and dimensions), short-beam shear strength, flexural strength, and dielectric strength at RT and 77 K.
D-17: Microstructural Processing and Phase Stabilization Analysis of Off-stoichiometric
Fe-Mn-Ga Shape Memory Alloy: Nana Adoo1; Nickolaus Bruno1; 1South Dakota School of Mines and Technology
Fe-based magnetic shape memory alloys (MSMAs) have been of great interest to the scientific community as they have been shown to exhibit a metamagnetic phase transition, namely a concurrent reversible martensitic transition and change in magnetic ordering. The multiferroic transitions in these alloys have potential application as energy harvesters, solid-state magnetic coolants, sensors, and actuators. Unlike Ni-based MSMAs, Fe-based MSMAs have been reported to exhibit better ductility, however, the effect of processing on phase stability and the metamagnetic behaviors have rarely been studied. This work shows that non-transforming phases can form in FeMnGa MSMAs with slow cooling after homogenization treatments and that the large transformation hysteresis observed in these alloys is heavily influenced by the microstructure and alloy composition. The structure-property relationships in FeMnGa MSMA are investigated over a range of compositions (e/a ratio) and we present possible processing methods and compositions useful for engineering stable and transformable Fe-based MSMAs.
D-18: Order-disorder Transition and Antiferromagnetism in Cu-Mn-Al BCC Alloys: Tatsuya Ito1; Xiao Xu1; Toshihiro Omori1; Kaoru Namba2; Takashi Saito2; Ryosuke Kainuma1; 1Tohoku University; 2J-PARC Center
Recently, antiferromagnetic alloys have been attracting attention in the field of spintronics, because a higher Néel temperature is favored for the applications. From the previous studies, we estimated that the Cu-Mn-Al alloys would have been antiferromagnetic with a high Néel temperature if they were in the B2 structure. However, it is difficult to retain the B2 because of easy ordering to the L21 (Heusler) structure during quenching. In this work, we focused on the way to decrease the B2/L21 order-disorder transition temperature by substituting Al with Cu or Mn, and we investigated their magnetic properties. The Cu2+xMnAl1-x and Cu2Mn1+xAl1-x samples were prepared by induction melting, and the order-disorder transition temperatures and magnetic properties were investigated for the quenched samples. As a result, we achieved antiferromagnetism with a high Néel temperature of 540 K in Cu50Mn35Al15 alloy.
D-19: Polyurethane Based Composites for Magnetic Actuator Applications: Antonio Veloso-Fernández1; Asier Aguilera-Grande1; Borja González1; José Manuel Laza1; Daniel Salazar Jaramillo2; Ana Catarina Lopes1; José Luis Vilas-Vilela1; 1University of Basque Country; 2BCMaterials- Basque Center for Materials, Applications and Nanostructures
The development of active materials, able to respond to an external stimulus, are a demand in the current era of Internet of Things (IoT). The ones with magnetic properties are particularly interesting due to their capacity to be wirelessly activated. Those are usually obtained by dispersing micro- or nano-sized magnetic particles into a polymeric matrix. Due to its thermoplastic properties, polyurethanes (PUs), stands out as an appropriated option.In this work, we aim to provide an insight on polyurethane based magnetic active material filled with different concentrations of CoFe2O4, in the range of 35-55 nm, and with different thickness. The process of synthesis was optimized and the morphological, mechanical and thermal characterization was performed. Finally, the actuator and magnetorheological behavior of the prepared composites were analyzed to improve their performance as microvalves in microfluidic devices.
D-20: The Effect of Stress-annealing on the Mechanical and Magnetic Properties in Fe-based Metal-amorphous Nanocomposites: Nickolaus Bruno1; Andrew Scherrer1; Elijah Meakins1; Ronald Noebe2; Alex Leary2; Vladimir Keylin2; Grant Feichter2; Maria Willard2; 1South Dakota School of Mines and Technology; 2NASA Glenn Research Center
Inductor cores comprised of planar-flow-cast Fe-based metal-amorphous nanocomposite (MANC) ribbons have been shown to exhibit a relatively high magnetic induction and low core losses at high excitation frequencies. However, they generally exhibit permeabilities that are too high for use in many filter applications. To overcome this issue and to decrease magnetic permeability, they can be annealed at temperatures above 500°C under high tensile stresses, using an in-line process known as stress-annealing (SA). SA is a difficult task, particularly for Fe-based alloys, due to the well-known embrittlement that takes place in metallic glasses after annealing at even moderate temperatures. The present work aims to understand and improve the SA process for a few compositions of Fe-based MANC ribbons through thermomechanical and mechanical characterization, identification of defects in as-cast precursor ribbons that lead to failure during processing, and by understanding the residual stresses and mechanical properties in SA and as-cast precursor material.