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text, 学術雑誌論文 / Journal Article, In order to improve the finishing efficiency of the Magnetic Abrasive Finishing process, we proposed a new MAF process with renewable abrasive particles using compound magnetic finishing fluid circulatory system in this paper. This new finishing process has a circulating system that uses a conveyor belt to renew the mixed abrasive particles. This not only maintains the stability of the finishing but also ensures that the processing does not need to be interrupted. In this study, we investigated the magnetic field distribution, finishing force, and finishing behavior of the processing area. Furthermore, we designed experimental device to finish the sus304 stainless steel plate, to verify the feasibility of this process and understand its characteristics through processing experiments. Moreover, the influence of important process parameters, including magnetic particles, abrasive particles, conveyor belt line speed and working gap, on the surface quality of the workpiece is studied through the experiment. The experimental results indicate that the present process can achieve stable processing of the material surface without interruption, and the surface roughness of the sus304 stainless steel plate has been improved from 273 nm to 23 nm through this process.

With the development of semiconductors, optics, aerospace, and other fields, the requirements for surface finish are constantly increasing. This requires not only better surface quality but also higher finishing efficiency. In order to improve the surface quality, the magnetic abrasive finishing process using an alternating magnetic field was proposed in the previous research. In this process, the magnetic clusters constantly fluctuate due to the periodic change of the current, thereby realizing the circulation of the abrasive particles in contact with the workpiece. It has been proved through previous studies that a better surface quality can be obtained in an alternating magnetic field. However, there are still some unclear mechanisms. For example, the fluctuation of magnetic cluster mainly depends on the change of current, but it is not clear which current change mode is more suitable for improving finishing efficiency and surface quality. Therefore, in this study, the influence of the current change mode on the magnetic field, finishing force, and finishing characteristics are discussed. Furthermore, SUS304 stainless steel plate was used as the object to conduct a series of experiments. According to the experimental results, when the abrasive particles are WA#8000, the average diameter of the magnetic particles is 75 μm, and the frequency is 1 Hz; in the case of pulse current with a duty cycle of 80%, a higher material removal rate can be achieved. The material removal rate is 1.7 times that of the static magnetic field and 1.45 times that of the sinusoidal alternating magnetic field.

Magnetic abrasive finishing (MAF) is an effective surface finishing method. At present, most of the research on plane MAF focuses on finishing characteristics. However, due to the “edge effect” of the magnetic field and the rotational movement of the magnetic brush, the uniformity and flatness of the finished surface are poor. In order to further improve the accuracy of the finished surface, the surface uniformity and flatness are improved by changing the shape of the magnetic pole and the trajectory of the magnetic brush. At the same time, the surface flatness is evaluated not only by the maximum height difference of the cross section but also by the standard deviation to evaluate the surface uniformity and flatness. Through magnetic field simulation and experiments, it is proved that the bottom groove of the magnetic pole helps to make the magnetic particle distribution more uniform in the processing area, which can effectively improve the surface quality. In addition, through experiments, changing the trajectory of the magnetic brush can also effectively improve the surface flatness of the finished surface.

In order to improve the machining efficiency of a traditional plane magnetic abrasive finishing (MAF) process, the MAF combined with an electrolytic process (EMAF) was proposed. Because the relation among the magnetic field, the electric field, and the flow field of the electrolyte is very complicated in the EMAF process, the machining mechanism has not yet been investigated clearly. In this paper, the mechanism of the EMAF process was investigated, and mainly discusses the influencing factors of finishing stability and surface quality. First, a set of current measurements and recording devices was designed to investigate the current changes during the finishing process. The measured current value curve was used to evaluate the processing status. Then, validation experiments were performed; the influence of the particle size and supply amount of magnetic particles on processing was observed. Experimental results show that it was clarified that the optimal experimental conditions existed, and the best results were obtained when using the electrolytic iron powder (330 μm in mean diameter) and a supply amount of 0.6 g.

In this paper, we propose a new plane magnetic abrasive finishing method, applicable to planes, that uses the alternating magnetic fields to solve problems such as the easy deformation and poor recovery of a magnetic brush in conventional magnetic abrasive finishing method. Compared with the magnetic brush used in conventional magnetic abrasive finishing, that in the new method can stably shape a workpiece under an alternating magnetic field. To determine the optimal finishing parameters, we focused on studying the effects of spindle rotational speed, size of diamond particle, and frequency of alternating magnetic field on the finishing surface. Then, according to the obtained optimal finishing parameters, multi-stage finishing experiments were performed with the new method. The results show that surface roughness can be improved from 230 nm Ra to 19 nm Ra in 60 min with the proposed method.

A magnetic abrasive nano-polishing process using low-frequency alternating magnetic field was developed for micro-grooves surface in this study. And by using alternating magnetic force produced by low-frequency (3 Hz) alternating magnetic field to make magnetic cluster generates a cyclical fluctuation of up and down, and then promotes the abrasives into micro-groove surface. A set of experimental devices were designed to investigate the effect of magnetic pole shape on magnetic field distribution and finishing characteristics. Final experiments were performed on glass and alloy steel specimens to examine the polishing performance for micro-groove surface. The glass initial surface roughness (Ra) of 123.38 nm, 130.71 nm, 136.08 nm, and 129.39 nm decreased respectively to 55.18 nm, 50.92 nm, 65.62 nm, and 62.42 nm and the groove surfaces obtained obvious improvement by this process. The surface roughness (Ra) of alloy steel is reduced as low as 68.70 nm from 192.48 nm, and the burr of edge and groove surface was removed effectively after 20-min polishing. It is demonstrated that this process is effective for deburring and improving micro-groove surface quality.

In order to achieve the finishing of complex microsurface, the magnetic abrasive finishing process using alternating magnetic field was proposed. In this paper, the mechanism of the magnetic abrasive finishing process using alternating magnetic field was investigated. At the same time, the influence of magnetic particle size and magnetic field frequency on magnetic cluster changes was observed and the relationship between finishing force and alternating magnetic field was analyzed. In addition, the feasibility of ultraprecision finishing of 5052 aluminum alloy plate through this process was studied, and the influence of relevant process parameters on the finishing characteristics was analyzed. The experimental results show that the surface roughness of 5052 aluminum alloy plate improved from 318 to 3 nm Ra in 15 min.

The magnetic abrasive finishing (MAF) process is an ultra-precision surface finishing process. In order to further improve the finishing efficiency and surface quality, the MAF process using an alternating magnetic field was proposed in the previous research, and it was proven that the alternating magnetic field has advantages compared with the static magnetic field. In order to further develop the process, this study investigated the effect on finishing characteristics when the alternating current waveform is a square wave. The difference between the fluctuation behavior of the magnetic cluster in two alternating magnetic fields (sine wave and square wave) is observed and analyzed. Through analysis, it can be concluded that the use of a square wave can make the magnetic cluster fluctuate faster, and as the size of the magnetic particles decreases, the difference between the magnetic cluster fluctuation speed of the two waveforms is greater. The experimental results show that the surface roughness of SUS304 stainless steel plate improves from 328 nm Ra to 14 nm Ra within 40 min.

In order to achieve the precision machining of the alumina ceramic surface, we propose surface finishing of alumina ceramic by the magnetic abrasive finishing (MAF) process using low-frequency alternating magnetic field. In previous studies, the effects of important process parameters on finishing force and finishing characteristics were investigated when the magnetic particle diameter was 6 and 30 μm. Due to the higher hardness of alumina ceramics, greater finishing force is needed, so we studied the effect of magnetic particle diameter and alternating magnetic field frequency on the finishing force. In order to determine the best experimental conditions, we study the effect of important process parameters on the finishing characteristics. The experimental results prove that the surface finishing of alumina ceramic can be achieved. The surface roughness of the alumina ceramic plate can be improved from 244.6 nm Ra to 106.3 nm Ra.

On the basis of ordinary plane magnetic abrasive finishing, a finishing method is proposed that can improve the flatness of a plane workpiece. In this method, the feed speed is varied during finishing according to the profile curve of the initial surface and the material removal efficiency, to control the effective finishing time in different areas and thereby improve the surface flatness. A small magnetic pole with an end face diameter of 1 mm is designed, and a ferromagnetic plate is placed under the workpiece to improve the uniformity of the magnetic field distribution near the magnetic pole. An experiment on an A5052 aluminum alloy plate workpiece shows that after 60 min of finishing using the proposed method, the extreme difference of the workpiece surface can be reduced from 14.317 μm to 2.18 μm, and the standard deviation can be reduced from 3.322 μm to 0.417 μm. At the same time, according to the measurement results, a similar flatness can be achieved at different positions on the finishing area. Thus, the proposed variable-speed finishing method leads to obvious improvements in flatness.

We proposed a new ultra-precision magnetic abrasive finishing (MAF) process using low frequency alternating magnetic field in this paper. Magnetic cluster themselves may produce the up and down movement change under alternating magnetic force. The movement may not only promote the dispersion of micro-magnetic particles, but also improve stirring effect and cross-cutting effects of the abrasives, achieving circulation and update to ensure the stability of grinding tools. This process is considered to be able to efficiently apply in ultra-precision finishing of plane and complicated micro-surfaces. In this study, we investigated the effects of alternating magnetic field on magnetic field distribution, finishing force and abrasive behavior. Furthermore, a set of experimental devices have been designed for finishing SUS304 stainless steel plate. The present work is aimed at understanding finishing particularity of this process and studying impacts of important process parameters namely grinding fluid, rotational speed of magnetic pole, current frequency on change in finish surface and material removal. Experimental results indicate that the process can realize ultra-precision finishing of plane by using oily grinding fluid. In the present research, the surface roughness of SUS304 stainless steel plate was improved from 240.24 nm to 4.38 nm by this process.