Synthesis Of High-Entropy-Alloy-Based Magnetic Alloys By Mechanical Alloying
dc.contributor.author | Rathi, Anuj | |
dc.contributor.advisor | Jayaraman, Tanjore V. | |
dc.date.accessioned | 2018-08-28T19:06:43Z | |
dc.date.available | 2019-09-04T20:15:39Z | en |
dc.date.issued | 2018-08-24 | |
dc.date.submitted | 2018-07-09 | |
dc.identifier.uri | https://hdl.handle.net/2027.42/145479 | |
dc.description.abstract | The objective of this thesis work was to synthesize high-entropy based magnetic alloys and investigate the phase evolution during the synthesis and thermal treatments. A thorough literature review was performed on magnetic high-entropy alloys. The ternary iron-cobalt-nickel alloys (Fe33.33Co33.33Ni33.33, Ni40Co30Fe30, Fe40Co30Ni30, Co40Fe30Ni30, and Fe46Co34 Ni20) and the quaternary iron-cobalt-nickel-silicon alloys (Fe40Co30Ni30)0.9Si0.1 were synthesized by mechanical alloying, followed by structural characterization of phase evolution by x-ray diffraction (XRD), scanning electron microscopy (SEM) and magnetic characterization by magnetometry. The Fe33.33Co33.33Ni33.33 alloy was formed after mechanical alloying for ~9 hours. The lattice parameter of the face-centered-cubic (f.c.c) alloy was ~0.3591 nm and the crystallite size was ~12 nm. The SEM revealed particle size (D90) ~15.9 µm. The alloy exhibited decent magnetic properties having saturation magnetization (MS) of ~136 ± 3 Am2/kg and coercivity (HC) of ~2.4 kA/m at room temperature. After the thermal treatment, Ms increased by ~14% and Hc decreased by 60%. Among the Ni40Co30Fe30, Fe40Co30Ni30, and Co40Fe30Ni30 alloys, the Fe-rich alloy mechanically alloyed for 12 hours showed superior magnetic properties. The Ms was ~148 ± 3 Am2/kg and the Hc was ~4.3 kA/m. The lattice parameter, crystallite size, and D90 was ~0.3574 nm, ~8 nm, and ~5.5 µm, respectively. Thermal treatment of the Fe-rich alloy improved its magnetic properties. It increased Ms by 10% and decreased Hc by 25%. The Fe46Co34 Ni20 showed the best magnetic properties among all, the Ms was ~167 ± 2 Am2/kg and the Hc was ~3.3 kA/m. Lastly, in the case of (Fe40Co30Ni30)0.9Si0.1 alloy, the Ms decreased by ~10% and the Hc increased by ~40% compared to Fe40Co30Ni30 alloy. A systematic study of magnetic properties of the iron-cobalt-nickel alloys is likely to provide the necessary foundation for the development of high-entropy based magnetic alloys by further alloying additions. | en_US |
dc.language.iso | en_US | en_US |
dc.subject | Magnetic alloys | en_US |
dc.subject | High-entropy alloys | en_US |
dc.subject | Magnetics | en_US |
dc.subject | Mechanical alloying | en_US |
dc.subject.other | Materials engineering | en_US |
dc.title | Synthesis Of High-Entropy-Alloy-Based Magnetic Alloys By Mechanical Alloying | en_US |
dc.type | Thesis | en_US |
dc.description.thesisdegreename | Master of Science in Engineering (MSE) | en_US |
dc.description.thesisdegreediscipline | Mechanical Engineering, College of Engineering & Computer Science | en_US |
dc.description.thesisdegreegrantor | University of Michigan-Dearborn | en_US |
dc.contributor.committeemember | Mohanty, Pravansu | |
dc.contributor.committeemember | Reyes-Villanueva, German | |
dc.identifier.uniqname | 81594862 | en_US |
dc.description.bitstreamurl | https://deepblue.lib.umich.edu/bitstream/2027.42/145479/1/49698122_20180711_anuj_rathi_thesis_embedded.pdf | |
dc.identifier.orcid | 0000-0002-1439-2776 | en_US |
dc.description.filedescription | Description of 49698122_20180711_anuj_rathi_thesis_embedded.pdf : Thesis | |
dc.identifier.name-orcid | Rathi, Anuj; 0000-0002-1439-2776 | en_US |
dc.owningcollname | Dissertations and Theses (Ph.D. and Master's) |
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