Application Of Rare Earth Permanent Magnet On Magnetic Abrasive Machining

Key Engineering Materials Vols. 336-338 (2007) pp. 712-714 online at http://www.scientific.net © (2007) Trans Tech Publications, Switzerland Application of Rare Earth Permanent Magnet on Magnetic Abrasive Machining Y. Chen1 and D.Y. Ju2 1 Department of Mechanical Engineering, Anshan University of Science and Technology, China 2 Department of Mechanical Engineering, Saitama Institute of Technology, Japan Keywords: Magnetic abrasive machining, Permanent magnet, Magnetic flux, Coercive force Abstract. Because of the raw material elements and its purity and so on, the Nd-Fe-B permanent magnet, the strongest magnetic material, which needs artificial synthesis, can hardly be used directly. The performance of the permanent magnet has not yet been greatly developed owing to the limitation of the artificial synthesizing technology, of the powder sintering technology and that of the application. In this paper, the magnetic abrasive machining method as a new application is put forward, and from this viewpoint, are discussed the performance and the processing technology of the permanent magnet and the magnetic abrasive machining method. A sintering route combining the direction heat treatment technique to increase the magnetic energy is suggested. Introduction In the permanent magnet materials domain, the development of the Nd-Fe-B permanent magnet has now undergone nearly 20 years. Through the raw material depuration, powder smelting, heat treatment, surface treatment and so on, each kind of technological progress in the Nd-Fe-B permanent magnet leads to the continuous enhancement of its permanent magnetic performance, which also needs to develop the new magnetic materials, and that a new application is to be sought for has become the common request. The magnetic abrasive machining is regarded as one kind of new permanent magnet application. The magnetic abrasive machining is a method in which the magnetic field (lines of magnetic force) is used to precisely machine the surface of the workpiece [1]. When the magnetic abrasive particles are filled between N-S magnetic poles, owing to the application of magnetism, the magnetic abrasive particles become a hard magnetic brush along the lines of magnetic force (The magnetization is generated). When the workpiece is inserted into this magnetic field, and when the relative movement between the workpiece and magnetic poles is given, the magnetic abrasive particles will press and polish the surface of the workpiece (Figure 1). Performance demand of permanent magnet There are a lot of factors that influence the processing efficiency and the quality of the magnetic abrasive machining. In the magnetic abrasive machining, the magnetic abrasive particles present a