Finishing Characteristics Research Articles

Metastable austenitic stainless steel tool for magnetic abrasive finishing

Through selective heat treatment, a metastable austenitic stainless steel tool can be fabricated to exhibit alternating magnetic and nonmagnetic regions. Magnetic abrasive is attracted to the borders of the magnetic regions of the developed tool to create additional finishing points. In combination with a multiple pole-tip system, this unique magnetic property facilitates simultaneous finishing of multiple regions for shortening finishing time. This paper describes the fabrication, the crystalline structure, and the resulting magnetic properties of the heat-treated tool. The magnetic abrasive behavior, the finishing characteristics, and a mechanism to extend the finished length are clarified for internal finishing flexible capillaries.

Material Removal Mechanism in Vibration-Assisted Finishing

In this paper, it is explored the material removal mechanism in vibration-assisted finishing process. On the basis of some experiments, the finishing characteristics are represented summarily. Though the analysis, it is shown that the vibration assistance method may increase cutting distance and speed of abrasive and material removal in per unit finishing distance which is affected by vibration frequency and amplitude, in-process abrasives behavior. What more, the increase in material removal rate is mainly due to an increase in material removal per unit finishing distance which is affected by the effects of abrasives cross-cutting.

Study of Internal Finishing Process for Capillary using Magneto-rheological Fluid

Capillaries, whose internal diameters are under 0.3 mm, are used for an injection pipe in medical field, an instrument in chemical and biological field. These capillaries are being required to be finished smoother to prevent a contamination etc. This paper studied a new finishing process using Magneto-rheological Fluid (MRF) of such capillaries, which are difficult to be finished by general processing techniques. In our previous study, we developed the MRF-based slurry, which is the composite of MRF and abrasive, and demonstrated the basic finishing characteristics and the finishing mechanisms. In this paper, we applied the MRF-based slurry to the internal finishing of capillaries using the motion of axial direction, and demonstrated the finishing characteristics and the finishing mechanisms. The higher magnetic flux density of the finishing area increased the finishing force and the dragged motion of the slurry by the magnetic poles; improved the finishing performance. And the edge effects of magnetic flux density also accelerated the finishing performance was found. The slurry showed the high dragged motion when the supplied amount of the slurry was accommodated to the area of high magnetic flux density. The higher velocity of magnetic poles decreased the dragged motion of the slurry; declined the finishing performance. The internal surface of SUS316L stainless steel tube (0.8mmID, 0.4mmID) could be finished smooth by the MRF-based slurry was confirmed.

Material Removal Mechanism in Vibration-Assisted Magnetic Abrasive Finishing

This paper proposed a viewpoint to explain why vibration assistance may increase material removal rate (MRR) in vibration-assisted magnetic abrasive finishing process. A series of experiments on vibration-assisted finishing have been carried out. On the basis of these experiments, the finishing characteristics are represented summarily. It was shown that the increase in material rate is mainly due to an increase in material removal per unit working distance.

Optimizing Electrochemical Buffing Control Parameters for Surface Finishing of Ultrahigh Purity Components

Electrochemical buffing technology (ECB) applies electrochemical and mechanical finishing characteristics in the surface finishing process. ECB can buff ultrahigh purity components to make them shine, without leaving residual stress, micro-cracks, and etc. The control parameters of the ECB process include current density, the rate of revolution of the buffing head, the buffing pressure on the surface, the concentration of electrolyte, the buffing time and others. Improper control parameter setting in the process will result in unsatisfactory surface quality. It is necessary to determine optimal control parameters of an ECB process with robust performance that can insure surface quality and process reliability. In this study, parametric analyses were conducted on electrochemical buffing technology.An ECB system with a CNC machine was established. The buffing head was clamped on the tool holder of the CNC machine. It was used on a flat surface for automatic surface buffing. Taguchi′s parameter design approach is employed to evaluate signal-to-noise ratios (SN) given from various levels of these factors. Then, the optimized control parameters will be recognized thus can get the optimal surface buffing, reducing with the lowest variability. The contribution of every factor to the sum of square is calculated. An experiment is performed using the optimal control parameters to confirm the results of the previous experiment. The results reveal that the ECB process yields the desired mirror-like surface.

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.

Study of Internal Magnetic Field Assisted Finishing for Copper Tubes with MRF (Magneto-Rheological Fluid)-Based Slurry

This research studied the internal magnetic field assisted finishing with MRF (Magneto-rheological Fluid)-based slurry for copper tubes.MRF-based slurry that included diamond abrasives was applied to the internal magnetic field assisted finishing for copper tubes and the finishing characteristics were studied. The results showed that the exciting current and the abrasive size changed the finishing characteristics of MRF-based slurry. This finishing process creates a smooth mirror finished surface with few directional cutting marks on the surface of the copper tube.

21501 プラズマ溶射法を利用した球状磁性砥粒に関する研究(研削・研磨加工-1,OS.14 研削・研磨加工)

Magnetic abrasive used for the internal finishing of capillary tubes is a composite particle, consisting of iron and Al_2O_3 abrasive grains. The irregularity of the magnetic abrasive shape, due to the mechanical refining process, results in the non-uniform depth of cut of the abrasive and restricts the improvement of the finished surface quality. These difficulties of the existing magnetic abrasive have resulted in a narrow range of finishing performance. Moreover, the irregularity of the magnetic abrasive shape brings the difficulty in merely introducing the magnetic abrasive into the capillary tubes. To break through the mentioned difficulties, this research develops a spherical iron-based magnetic abrasive made using by plasma spray, which carries Al_2O_3 grains on the surface. This paper discusses the effects of the methods of mixing the iron particles and abrasive grains, a pre-process to the plasma spray, on the finishing characteristics of the magnetic abrasive.

Study of Internal Finishing of Austenitic Stainless Steel Capillary Tubes by Magnetic Abrasive Finishing

This paper studies the internal finishing of capillary tubes using a magnetic abrasive finishing process. Such tubes are used with nanoscale technologies and meet the demands of the present age in medical and chemical equipment. The finishing characteristics are influenced by the magnetic abrasive behavior against the inner surface of the capillary, which is controlled by the supplied amount of magnetic abrasive and the magnetic force acting on it. The development of the finishing unit identifies the characteristics of the magnetic field, which controls the magnetic force, required for the necessary magnetic abrasive behavior. Finishing experiments using SUS304 austenitic stainless steel capillary tube with 800μm inner diameter demonstrate the effects of the supplied amount of the magnetic abrasive on the finishing characteristics, and the results suggest a standard method to determine the amount to achieve sufficient finishing. The run-out of the capillary while rotating at high speed under the cantilever tube support method causes instability of the magnetic abrasive behavior. The effects on the finishing characteristics are discussed, and a method to diminish the run-out is applied. Accordingly, this paper presents the conditions required for the internal finishing of capillary tubes and proposes methods to realize them. The internal finishing of 400μm inner diameter capillary tubes conveys an understanding of the mechanisms involved and demonstrates the usefulness of the proposed methods.

A new approach to appearance characterization

AbstractA proposal to characterize appearance in three different categories—color, cesia, and spatial properties or spatiality—is made. Color will include whiteness and yellowing and is related to optical power spectral properties of the stimulus detected by observers. Cesia will include transparency, translucence, gloss, luster, haze, lightness, opacity, matt, etc., and is related to the properties of reflecting, transmitting, or diffusing light by objects or materials evaluated by human observation. Spatial properties are divided in two main groups: (1) modes of appearance in which color is modified depending on the angle of observation related to the light incidence angle, such as metallic, pearlescent, or iridescent materials, and (2) modes of appearance related to optical properties of surfaces or objects in which effects of ordered patterns (textures) or finishing characteristics can be described by spatial filtering (roughness, polish, distinctness of image, orange peel, etc.). © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 164–167, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20205

On simulation of magnetic abrasive finishing process for plane surfaces using FEM

In this paper, a finite element model is developed for the plane Magnetic Abrasive Finishing (MAF) process, by considering the problem as an axisymmetric magnetostatic problem. The model is validated with the available experimental results in the literature. A theoretical model for stock removal and surface roughness is developed by considering the indentation of the magnetic abrasive grain on the workpiece surface. The effect of various process parameters such as magnetic flux density, size of MAP, rotational speed of tool, finishing time, initial surface roughness and shape of abrasive grain on the finishing characteristics are studied. An attempt is made to determine an index of surface roughness for better understanding of the effect of above process parameters on the surface roughness.

Bovine tissue mRNA abundance related to acute cold exposure and acute feeding restriction

Thirty-six steers were used to determine the effects of acute cold (-20°C) and acute feed restriction (0.4× maintenance) on mRNA abundance of five candidate genes. To investigate adaptational physiology in cattle we evaluated gene expression patterns for uncoupling protein 2 (UCP-2), uncoupling protein 3 (UCP-3), leptin, leptin receptor and neuropeptide Y receptor (NPY receptor) in specific tissues. We measured relative mRNA abundance using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) on mRNA extracted from duodenum, iver, skeletal muscle, mesenteric adipose tissue, subcutaneous adipose tissue, and peri-renal adipose tissue. We obtained carcass grades for comparison to mRNA abundance profiles. Leptin receptor mRNA abundance was increased by acute feed restriction in the liver (P = 0.02) and trended to increase in the duodenum (P = 0.06) of acute feed-restricted steers. NPY receptor RNA abundance decreased (P = 0.02) in the liver of feed-restricted steers, and acute cold-stress-treated steers (P = 0.03), but increased (P = 0.03) in mesenteric adipose tissue of acute-cold-treated steers. Leptin mRNA abundance was decreased in subcutaneous adipose tissue (P = 0.04) by acute cold, but trended to increase in the peri-renal adipose tissue (P = 0.09). UCP-3 mRNA abundance was not significantly altered by our acute treatments. UCP-2 mRNA abundance increased in subcutaneous adipose tissue of both acute cold (P = 0.004) and acute feed-restricted steers (P = 0.03) and in biceps femoris, after acute cold (P = 0.003) and acute feed restriction (P = 0.002). There was an inverse relationship between the leptin mRNA abundance in subcutaneous adipose and the carcass grade, where the AAA , AA and A grade carcasses had mean values of 501.6 ± 30.0, 535.5 ± 14.0 and 653.4 ± 61.0. Our results show that tissue-specific mRNA abundance of these candidate genes may be altered by acute stressors, and that may relate to tissue-specific adaptational strategies in cattle. Furthermore, leptin mRNA abundance in subcutaneous adipose tissue may inversely reflect the maturity or finishing characteristics of beef cattle such that it is inversely related to the final carcass grade. Key words: Acute cold, acute feed restriction, UCP-2, UCP-3, leptin, leptin receptor, NPY receptor, cattle

21003 微細径超硬合金の精密磁気研磨(生産・加工(1))

The implementability of the high precision magnetic abrasive finishing technology over cemented carbide slender work used for the diameter punch of detailed was examined. In this paper, the effects of the clearance between work surface and magnetic pole, and the particle diameter of diamond abrasive and ferrous particle are examined on the finishing characteristics. As a result, it's effective find out that the clearance was narrow and the particle diameter of diamond abrasive and ferrous particle was small. It's concretely, in the work-pole clearance on 0.5mm and mixed abrasive at the diamond paste whose mean particle diameter is 0.25μm and a ferrous particle using iron particles whose mean particle diameter is 30μm, 1.9μmRz of surface roughness has been improved to 0.07μmRz, and 1.2μm of roundness has been improved to 0.6μm. These results and a machining mechanism are reported.

Study of Internal Finishing of Slender Tubes by Magnetic Abrasive Finishing(Surface and edge finishing)

This paper studies the application of the Magnetic abrasive finishing process to the inner surfaces of slender tubes (with inner diameters less than 1mm), which meet the demands of the present age in medical, electrical, and chemical equipment. This paper develops the finishing equipment for internal finishing of slender tubes to realize the processing principle. Finishing experiments using SUS304 stainless steel tubes demonstrate the finishing characteristics and convey an understanding of the mechanism involved. This study achieves smoothly finished tubes with 800μm ID and also suggests the finishing conditions required for the success of the process for slender tubes in general.

Study on the inner surface finishing of tubing by magnetic abrasive finishing

With the development of industry manufacturing technology, fine surface finish is in high demand in a wide spectrum of industrial applications. Presently, it is required that the parts used in manufacturing semiconductors, atomic energy parts, medical instruments and aerospace components have a very precise surface roughness. Amongst them, vacuum tubes, wave guides and sanitary tubes are difficult to polish by conventional finishing methods such as lapping, because of their shapes. The surface roughness of these tubes affects the performance of the entire system, but the finishing technology for these tubes is very scant in manufacturing fields. This project was proposed by a Shanghai Far East pharmaceutial and mechanical factory. They stated that the roughness of the inner surface must be less than 0.3 μm Ra after finishing. An internal magnetic abrasive finishing (MAF) process is proposed for producing highly finished inner surfaces of tubes used in this study. The process principle and the finishing characteristics of unbounded magnetic abrasive within internal tubing finishing are described first. MAF setup was designed for finishing three kinds of materials tubing, such as Ly12 aluminum alloy, 316L stainless steel and H62 brass. Experimental results indicated that finishing parameters such as polishing speed, magnetic abrasive supply, abrasive material, magnetic abrasive manufacturing process and grain size have critical effects on the material removal rate (MRR). How the inner surface micro shape changes course during finishing of an aluminous tube is demonstrated.

Study of magnetic field assisted mechanochemical polishing process for inner surface of Si 3N 4 ceramic components : Finishing characteristics under wet finishing using distilled water

This study discusses the finishing characteristics of a magnetic field assisted mechanochemical polishing process using Cr 2O 3 abrasive mixed with magnetic particles in the case of wet finishing using distilled water, which was proposed for internal finishing of Si 3N 4 fine ceramic tubes. It was clarified that a highly accurate finishing can be achieved more efficiently in the case of wet finishing using distilled water compared with dry finishing. Moreover, those conditions necessary to achieve high efficiency finishing are discussed.

Internal finishing process for alumina ceramic components by a magnetic field assisted finishing process

This study presents the application of a new technique, magnetic field assisted finishing, for finishing of the inner surfaces of alumina ceramic components. The experiments performed on alumina ceramic tubes examine the effects of volume of lubricant, ferrous particle size, and abrasive grain size on the finishing characteristics. The finished surface is highly dependent on the volume of lubricant, which affects the abrasive contact against the surface; on the ferrous particle size, which changes the finishing force acting on the abrasive; and on the abrasive grain size, which controls the depth of cut. By altering these conditions, this process achieves surface finishes as fine as 0.02 μm in surface roughness ( R a) and imparts minimal additional residual stress to the surface. This study also reveals the mechanism to smooth the inner surface of alumina ceramic tube and to improve the form accuracy, i.e. the roundness of inside the alumina ceramic tube.

Electrolytic magnetic abrasive finishing

Electrolytic magnetic abrasive finishing (EMAF) is a compound finishing process, involving traditional magnetic abrasive finishing (MAF) and an electrolytic process. The aim of including the electrolytic process into the EMAF system is to produce a passive film (or oxide film), which is much easier to remove than the original metal surface during processing. Moreover, in the presence of both electric and magnetic fields, the negatively charged ions move toward the anode surface along a cycloid curve by the action of the Lorentz force. Under appropriate operating conditions, this phenomenon promotes electrolytic effects, resulting in a further increase in finishing efficiency, yielding a superior surface. This study describes the principles of the process, the finishing characteristics of surface roughness and material removal, and the associated mechanisms. Experimental results show that the EMAF process yields quite excellent finishing characteristics, better than those obtained by MAF, especially with a high electrolytic current. The process parameters such as electrolytic current, electrode gap, magnetic flux density, and rate of workpiece revolution must be appropriately fitted to obtain a superior refined surface with high efficiency.

高速流動法によるステンレス鋼管内壁面の研磨

High speed flow finishing method has recently developed, which has an excellent performance for polishing an inner wall of stainless steel capillary D Present paper focuses on the finishing characteristics of the inner wall of stainless steel pipe with high speed flow finishing method D It is found that bar-type mandrel inserted into the hole of pipe has great performance in finishing, in which a diameter of mandrel is slightly smaller than inside diameter of the pipe D Experiments indicate that surface roughness of the inner wall of pipe decreases with the number of slurry flow pass D It is shown that both of larger grain size and higher concentration of the abrasive in water solvent, have a greater finishing rate of the pipe D. It is described that larger flow pressure of slurry yields greater surface roughness decrease D

Study on cylindrical magnetic abrasive finishing using unbonded magnetic abrasives

The process principle and the finishing characteristics of unbonded magnetic abrasive within cylindrical magnetic abrasive finishing are described in this study. The unbonded magnetic abrasive is a mechanical mixture of SiC abrasive and ferromagnetic particles with a SAE30 lubricant. Iron grit and steel grit, for which three various particle sizes were prepared for both, were used as ferromagnetic particles, each of them being mixed with 1.2 and 5.5 μm SiC abrasive, respectively. Also, the finishing characteristics on surface roughness and material removal as well as their mechanisms were investigated. Experimental results indicate that steel grit is more suitable for magnetic abrasive finishing because of its superior hardness and the polyhedron shape. The variations of material characteristics on the work surface both before and after finishing were also investigated. Si content was increased obviously, however its corrosion resistibility decreased on a surface that was finished via steel grit mixed with SiC abrasive.