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Study on the Process, Microstructure and Magnetic Properties of Sm2Fe17Nx Magnets with HDDR

Author: LiFang
Tutor: LiuYing
School: Sichuan University
Course: Materials Science
Keywords: Sm2Fe17Nx magnet Single-phase Sm2Fe17 Homogenization Treatment HDDR Nitride
CLC: TM271
Type: Master's thesis
Year: 2005
Downloads: 98
Quote: 0
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Abstract


The HDDR prepared Sm the 2 the Fe 17 the N x magnet process is a very complex process, magnetic energy is good or bad is affected by many factors the impact this article by the microstructure of the alloy in the preparation process and its process, the study of the impact of the final magnetic properties of Sm 2 Fe 17 N x magnet preparation process was optimized. And guidance for the future direction of development and the existing problems. Studies have found that the use hysteresis plus SM and strict control of the melting power smelting technology of the time as possible to reduce the volatilization of Sm, melting, with the raise of the ingot cooling speed, the α-Fe of the branch crystal grew to be effectively controlled, the alloy each phase in grain refinement and improved efficiency for the subsequent step. Through the study of the micro-structure of the alloy of the different cooling rate, the cooling rate of the alloy ingot is optimized. The alloy during the melting process, Sm volatilization inevitably Sm compensation amount is too much or too small, can not get close to the single phase SM 2 Fe 17 of the alloy, through the different SM compensation amount of the Sm-Fe alloy before and after annealing the tissue changes the study to determine the best compensation amount of Sm. And on this basis, the Sm-Fe alloy of different annealing time and phase composition analysis, and to determine the optimal annealing temperature and time. The phase composition and microstructure analysis of the different stages of the Sm-Fe alloy HDDR process, summarize HDDR the mechanism of action of the Sm-Fe alloy and alloy phase composition evolution law. And through its further analysis of the role of the principle of the HDDR Process microstructure change to establish a physical model, theoretical research on improved. After the HDDR process Sm 2 of Fe 17 alloy powder particle size is unchanged, but the grain of powder has been produced in the refinement, the HDDR process micro cracks is nitrogen of providing a channel the Sm 2 Fe in 17 alloy powder activity has been significantly improved. The preliminary study also nitride process and nitride mechanism of Sm-Fe alloy, and can generally determine the appropriate nitriding process. By different milling time, the hydrogen process and the recombination process and Sm 2 Fe 17 N the x study of the relationship between the magnetic properties, determine the appropriate milling time of 20min, suitable hydrogenation process for slow heating up to 750 ℃ ??for for one hour after the low-temperature hydrogen-the appropriate recombination process 800 ℃ for 2h. Process optimization

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CLC: > Industrial Technology > Electrotechnical > Electrical materials > Magnetic materials,ferrite > Magnetic materials, ferromagnetic materials
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