Yan Hua Zou

Development of Effective Magnetic Deburring Method for a Drilled Hole on the Inside of Tubing Using a Magnetic Machining Jig

A new magnetic deburring method for a drilled hole on the inside of tubing is proposed in this study. This internal deburring method applies the magnetic field assisted machining process by using a magnetic machining jig (permanent magnet tool). In this research, we examined experimentally the deburring of a drilled hole on the inside of SUS304 stainless steel tubing. A processing unit and magnetic machining jig were made, and the processing unit was set on a lathe machine. The deburring experiment was performed for a drill hole 3 mm in diameter. The results showed that the internal burr could be removed using this magnetic deburring process and the height of the burr could be successfully decreased from 163 μm to 1 μm. Thus, it was proved that this magnetic deburring method was effective for the internal deburring of long tubing.

Study on Plane Magnetic Abrasive Finishing Process - Experimental and Theoretical Analysis on Polishing Trajectory -

This research studies an effective polishing process to elevate the surface precision and homogeneity by improving the polishing trajectory of magnetic brush. The moment of magnetic brush is a key influence factor on finishing characteristics, but in conventional plane magnetic abrasive Polishing process, the movements of magnetic brush is relatively simple. In this paper a polishing process using the complex polishing trajectory of magnetic brush has been modified and studied by use of newly designed experiment device. The linear movement of workpiece, the rotation and revolution or movement in XY coordinate plane of magnetic brush can be realized by this device. In comparison with conventional method, variation regularity about surface roughness and the material removal are been studied. According to experimental results for polishing trajectory of magnetic brush, finishing characteristics was clarified. The results show that studies on polishing trajectory of magnetic brush are more valuable and the experimental researches are consistent with theoretical analysis. In addition, the accuracy of plane magnetic abrasive finishing can be elevated in terms of the reasonable planning for polishing trajectory of magnetic brush.

Magnetic Abrasive Finishing of Internal Surface of Aluminum Pipe Using Magnetic Machining Jig

Magnetic abrasive finishing technology has been known very well in finishing of stainless steel SUS304 pipes to mirror finish standard. However, the applications in softer metal such as aluminum A2017 were difficult due to soft metal characteristic itself. In 2002, Zou and Shinmura had developed a new method of magnetic field assisted machining process using magnetic machining jig for SUS304 pipe [. The development has since then expanded in many research. This research finds the optimum finishing condition for mirror finish standard in internal surface of aluminum A2017 pipe. We use a 100% polyester fabric that does not cause scratch on the material and found that the optimum pole-pipe gap to be 13mm to achieve the best surface roughness Ra of 0.020μm after finishing, from surface roughness Ra of 0.195μm before finishing.

Study on Internal Magnetic Field Assisted Finishing Process Using a Magnetic Machining Jig for Thick Non-Ferromagnetic Tube

This paper describes an internal finishing process for thick non-ferromagnetic tube (10~20 mm in thickness) by the application of a magnetic field-assisted machining process using a magnetic machining jig (permanent magnet tool). In this study, a new automatic inner surface finishing system was developed, and to achieve smooth surface roughness and high form accuracy, a multiple-stage machining which contains of rough machining and precision finishing was carried out. Especially, in order to improve the form accuracy the rough processing time was made longer compared with the research in the past. The experiments were performed for a thick SUS304 stainless steel tube 10 mm in thickness. The results showed that surface-roughness and form accuracy were able to be improved greatly, the initial surface roughness of 4.9μm Ra can be improved to 0.01 μm Ra and the roundness of inside tube can be improved from 206 μm to13μm.

A New Internal Magnetic Field Assisted Machining Process Using a Magnetic Machining Jig-Machining Characteristics of Inside Finishing of a SUS304 Stainless Steel Tube

This paper proposes a new magnetic field assisted machining process using a magnetic machining jig (permanent magnet tool) to finish the internal surface of thick tubing 5~30 mm in thickness. Because the magnetic machining jig consists of permanent magnets, it can generate a higher magnetic force (finishing force) than conventional magnetic abrasives, and makes possible the internal finishing of thick non-ferromagnetic tubing. First, the principle and the feature of this process were examined. It was compared that the difference of the mechanism of using the conventional magnetic abrasives and magnetic machining jig (magnet tool) was clarified. Next, a processing unit and magnetic machining jig were made, and the processing unit was set on a lathe machine. An experiment was performed on a thick SUS304 stainless steel tubing 5 mm in thickness. In this study, it was clarified that this processing method can improve the roundness of the inside tubing while improving the surface roughness. The results showed that the initial surface roughness of 6.5 μm Ra can be improved to 0.06 μm Ra, and the roundness of the inside tubing can be improved from 187 μm to 89 μm.

Mechanism of a Magnetic Field Assisted Finishing Process Using a Magnet Tool and Magnetic Particles

This paper describes a new efficient internal finishing process for a thick tubing (10~30mm in thickness), by the application of a magnetic field-assisted machining process using a magnet tool. Because a stronger magnetic force can be generated than conventional magnetic abrasives, it makes the internal finishing of thick non-ferromagnetic tubing possible. Moreover, in order to obtain a high-quality surface, this process method was developed using magnetic particles magnetically attracted on the magnet surface. This paper characterizes the processing principle and advantages of this process. Then, the mechanism of this finishing process was examined by a plane model experiment. It was clarified that the magnetism and shape of a magnetic particle influence realization possibility of this processing method, and it also influence the finishing characteristics.

A Study on the Magnetic Field Assisted Machining Process for Internal Finishing Using a Magnetic Machining Jig

This paper describes a new efficient internal finishing process for a non-ferromagnetic thick tube of 10-20 mm in thickness by the application of a magnetic field assisted machining process using a magnetic machining jig, which consists of a rare earth permanent magnet, as a tool, instead of the conventional magnetic abrasives. In contrast to the magnetic abrasives, it can generate a stronger magnetic force, which is the finishing force, due to higher material susceptibility, and makes internal finishing of a non-ferromagnetic thick tube possible. The principle and advantages of this process are described. The finishing experiment was carried out and the finishing characteristics are described. The results showed that this process enables precise internal finishing of thick non-ferromagnetic tubes, such as the SUS304 stainless steel tube of 10 mm in thickness. The initial surface roughness of 4.5 μm in Ra was improved to 0.1 μm in Ra. Introduction An internal magnetic abrasive finishing process was developed for generating high-quality inner surfaces of tubes and gas bombs used in critical applications such as in clean gas or liquid piping systems. In the previous reports [1] [2], the finishing characteristics and mechanism of the thin non-ferromagnetic tube (under about 4 mm in thickness) using magnetic abrasives have been clarified. However, it is difficult to finish internal surfaces of thick tubes and clean gas bombs (10~20 mm in thickness) by the conventional finishing process using the magnetic abrasives, because magnetic force (finishing force) weakens when the thickness of tube becomes thick. A new efficient process for internal finishing of a non-ferromagnetic thick tube has been proposed [3]. In this process, magnetic field-assisted machining using a magnetic machining jig that consists of rare earth permanent magnets wrapped with abrasive paper is employed instead of conventional magnetic abrasives. Moreover, a model experiment in which a brass plate (10 mm in thickness) was used as a work was carried out, and it was shown that finishing could be achieved by using this new process. Moreover, this new process was developed using magnetic particles that are magnetically attracted to the surface of a permanent magnet of a magnetic machining jig and using abrasive slurry. While the magnetic machining jig follows the rotation of pole through the magnetic particles, the relative motion against the inner surface of tube is generated, the abrasive behavior is indirectly given from magnetic particles to abrasive grains, the precise finishing is achieved. In this paper, the advantages of using a magnetic machining jig are clarified by comparing the merits and demerits of the method using magnetic abrasives and the method using a magnetic machining jig. Next, the principle and advantages of this new process for an internal magnetic abrasive finishing using a magnetic machining jig are described. Finally, the magnetic machining jig and the experimental setup applied to the internal finishing of thick tube were manufactured, and an experiment on internal finishing of a thick tube using the magnetic machining jig was carried out for the first time. A two-step process was used in this experiment to obtain a high-quality surface. In the first step, an abrasive cloth was boned on the surface of the magnetic machining jig, and in the second step, magnetic particles were magnetically attracted to the surface of magnet of the magnetic Key Engineering Materials Online: 2004-02-15 ISSN: 1662-9795, Vols. 257-258, pp 505-510 doi:10.4028/www.scientific.net/KEM.257-258.505

Development of a New Ultra-Precision Magnetic Abrasive Finishing Process

To obtain an ultra-precision surface, this research developed a new type of magnetic finishing tool, “Ultra-precision Magnetic Abrasive Slurry”, for a magnetic field assisted internal finishing process. This ultra-precision magnetic abrasive slurry is made to mix simply the super-minute abrasive grains, super-minute globular iron particles, and oily grinding liquid. When the internal finishing was executed, the automatic mixing phenomenon of the Ultra-precision Magnetic Abrasive Slurry is caused, at the same time, super-minute abrasive grains and minute iron particles were uniformly distributed to the magnetic abrasive slurry. It was confirmed that a smooth mirror internal finishing for a SUS304 stainless steel tube is able to be achieved, by using the Ultra-precision Magnetic Abrasive Slurry that consists of the globular carbonyl iron particles (6μm in mean diameter) and diamond grains (0.25~0.75μm in mean diameter) and the oily grinding liquid. In this study, we examined the influence that the rotational speed of the magnetic pole exerted on the finishing characteristic. The results showed that the ultra-precision surface is successfully made, and the surface roughness has been improved from 320nm Ra to 3.37nm Ra .

Study on a Magnetic Deburring Method by the Application of the Plane Magnetic Abrasive Machining Process

This research studies the influence　of constant pressure acting on the magnetic particles brush for the precision machining of planar and curved workpieces. In particular, it examined the effects of constant pressure on improving the formal accuracy of the workpiece. This process method, constant pressure is applied to the magnetic pole of a conventional magnetic brush, the constant pressure acted to the surface of the workpiece through the magnetic particle brush formed at the magnetic pole surface. The authors conducted a plane magnetic abrasive finishing experiment using both the conventional magnetic abrasive finishing process and the newly proposed constant-pressure magnetic abrasive finishing process to compare the deburring characteristics between the processes for removing burrs from holes drilled in brass plate workpieces. In this experiment, a brass disk with a drilled hole was used as a workpiece. As a result, the difference in finishing characteristics was clarified. The results showed that the burr can be removed by use of this new plane magnetic abrasive finishing process and it is more useful than the conventional magnetic brush for improving the shape accuracy of the workpiece.