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Process to Improve the Performance of Rare-Earth Permanent Magnet NdFeB

Author: WangXiaoWei
Tutor: YanGaoLin
School: Harbin Institute of Technology
Course: Materials Processing Engineering
Keywords: Rare earth permanent magnet Proliferation Magnetic properties
CLC: TM273
Type: Master's thesis
Year: 2008
Downloads: 199
Quote: 0
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Abstract


Permanent magnet materials has become the foundation of modern science and technology, such as computer technology, information technology, aerospace technology, communication technology, transportation technology, office automation technology, home appliance technology and human health, and health care and other important material. Now used permanent ferrite, alnico and rare earth permanent magnet materials. Include samarium cobalt and neodymium iron boron rare earth permanent magnet, which has a record of high remanence, high coercivity, high energy product NdFeB become Magneto. China has 80% of the world's reserves of rare earth mineral resources, rare earth permanent magnet materials are widely used in people's lives. A need for efficient electrical and mechanical energy conversion, rare earth permanent magnet materials are essential, it can not only significantly reduce the weight of the machinery, it Dimensions decreases, and energy efficient results and improve motor performance, especially important to point out the high-performance rare earth permanent magnet materials and sustainable development are closely related. The world's oil resources shortage and fuel automobile emissions of carbon dioxide causes global warming makes large-scale development of clean energy and transport has become urgent. With the development of science and technology, with a strong and stable performance rare earth permanent magnet motor will gradually move toward people's lives. The motor's core technology is the use of ultra-high-performance rare earth permanent magnet materials. Despite the rare earth permanent magnet material has superior magnetic properties, but it has a serious weakness: the relatively poor thermal stability. The problem will make the material fails completely so that the electric car was completely paralyzed. Overcome this shortcoming of the magnetic material became key. This problem is a worldwide problem, and years of research, we have experimental evidence to show that the study has good prospects. The basic method to solve this problem: to optimize the treatment process, adjusting the composition and structure of the rare earth permanent magnet materials, Dy alloy added to improve the local anisotropy of the ferromagnetic material having a high magnetic anisotropy field, to prevent the expansion of the reverse magnetic domains; is controlled by the treatment process at the same time, optimizing the structure of the microstructure, and thus improve the coercive force at the same time, successful slow decline of remanence; at elevated temperatures, in order to achieve ultra-high coercivity to compensate for the loss of the magnetic flux. The specific use of the herein process is a high temperature diffusion heat treatment, i.e. into the vicinity of the temperature of the liquid diffusion in the Nd-rich grain boundary phase, in order to increase the amount of diffusion, either effective control of the added amount of the rare earth elements Dy, the process is very easy are widely used in industrial fields. : In the help of a scanning electron microscope, the micro-structure of the sample observed before and after the contrast diffusion different and diffusion of Dy element distribution; the help of X-ray diffraction to observe the phase change of the sample before and after contrast diffusion; vibrating sample the help of a magnetometer, the observed changes in the magnetic properties of samples for comparison. Analysis of the conclusions summarized above, and then get the optimum process parameters.

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CLC: > Industrial Technology > Electrotechnical > Electrical materials > Magnetic materials,ferrite > Permanent magnet materials, permanent magnet
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