Magnetic Compound Fluid Research Articles

The Most Suitable Clearance in MCF (Magnetic Compound Fluid) Polishing

Prof. Shimada has demonstrated experimentally that the polishing effect using our developed intelligent fluid, magnetic compound fluid (MCF), is greater than that using previously developed intelligent fluids, i.e., magnetic fluid (MF) and magneto-rheological fluid (MRF). Shimada succeeded in float polishing with a large clearance utilizing a newly developed magnetic responsive fluid, MCF, which was improved by the addition of a-cellulose, thereby achieving a clearance as great as 8mm. He also clarified the mechanism of the new polishing technique. A comparison of the MCF polishing effect with those of techniques using the ordinary magnetic responsive fluids, MF and MRF, showed the polishing effect of MCF to be greater than those of MF and MRF. The MCF polishing technique is applicable to many types of polishing, widening the variety of the uses of magnetic float polishing (MFP). However, while clearance to8mm is possible, this may not be the most suitable value. In this study, we clarified the most suitable value for MCF abrasion experimentally.

Feasibility study on surface finishing of miniature V-grooves with magnetic compound fluid slurry

Towards the development of a novel polishing technique for the high-precision surface finishing of miniature V-grooves, the feasibility of finishing linear V-grooves generated on an oxygen-free copper substrate using a magnetic compound fluid (MCF) slurry was experimentally investigated, and the fundamental finishing characteristics were elucidated. First, a polishing apparatus was constructed by installing an MCF unit for generating a rotary magnetic field and rotating an MCF carrier onto a polisher, along with a wave maker used for vibrating the workpiece. Then, polishing experiments were performed to clarify the fundamental polishing characteristics, including the effects of the polishing time on the material removal, the form accuracy (i.e. the form retention rate and symmetry error), and the surface roughness at different polishing locations/positions in the polishing zone. Thereafter, the fundamental characteristics were examined by investigating the distribution of abrasive particles in the polishing zone, the relative velocity of abrasive particles compared to the V-groove, and the impact angle of abrasive particles against the V-groove side surface. Finally, the effect of the MCF carrier rotation speed nc on the characteristics was elucidated, and an appropriate value of nc was proposed. The main results can be summarized as follows. (1) At the majority of locations in the polishing zone, the surface quality Ra at higher positions on the V-grooves was better than that at lower ones. At locations where abrasive particles moved from the right/left side to left/right side of the grooves, the surface quality Ra on the right/left side was better than that at the left/right side. The final surface roughness after 150min of polishing was in the range of 15–50nm Ra, indicating that a mirror-like surface could be successfully achieved for a miniature V-groove using the proposed technique. (2) The V-groove form accuracy, i.e. form retention rate η and symmetry error ɛ, deteriorated during polishing, and the final form accuracy differed with the location. Nevertheless, the η and ɛ values at the location where the form accuracy was the lowest were greater than 99.47% and less than 0.17, respectively. (3) Increasing the MCF carrier rotational speed nc deteriorated the form accuracy but improved the surface quality Ra. Taking into account the balance between the form accuracy and surface quality Ra, nc should be set at 10rpm under the experimental conditions in the current work.

Detailed Mechanism and Engineering Applicability of Electrolytic Polymerization Aided by a Magnetic Field in Natural Rubber by Mechanical Approach for Sensing (Part 2): Other and Intrinsic Effects on MCF Rubber Property

The same ordinary electrolytic polymerization of plastic-type polymer solution is applicable to natural rubber, with its C=C bonds, if a magnetic field and a filler are added. With the application of a magnetic field and the magnetic responsive fluid known as magnetic compound fluid (MCF), we have clarified the enhancement of the electrolytic polymerization of NR-latex and the growth of the thickness of vulcanized MCF rubber that results from the addition of a magnetic field. The present new method of MCF rubber vulcanization is effective for use in haptic sensors, which are used widely in various engineering applications. In the previous report, part 1 of this study, we investigated many experimental conditions under mechanical approach for sensing: magnetic field strength; applied voltage; electrodes gap; mass concentration, and the ingredients of the MCF. In the present sequential report, part 2, we investigate many other effects on electrolytic polymerization by the same mechanical approach for sensing as in part 1: the Mullins effect; the Piezo effect; vibration; kind of electrode; atmospheric gas. In particular, we clarify that the voltage generates spontaneously in the MCF rubber and that the MCF rubber becomes a Piezo element. These effects on the electrolytic polymerization as well as the effects of the experimental conditions will be useful in engineering applications. By taking the above-mentioned parameters and effects into account, MCF rubber that is electrolytically polymerized with the aid of a magnetic field, the use of MCF as a filler, and doping, can be useful in haptic sensor applications. In particular, the effectiveness of the Piezo element can be shown.

Detailed Mechanism and Engineering Applicability of Electrolytic Polymerization Aided by a Magnetic Field in Natural Rubber by Mechanical Approach for Sensing (Part 1): The Effect of Experimental Conditions on Electrolytic Polymerization

Ordinary electrolytic polymerization has involved plastic-type polymer solutions. Rubber, especially natural rubber, is one such polymer solution. Rubber has not been focused on until recently due to the fact that electrolytic polymerization has only a very small effect on rubber. However, when we focus on the C=C bonds of natural rubber, the same electrolytic polymerization is applicable to be enlarged on the natural rubber if a magnetic field and a filler are added. With the application of a magnetic field and a magnetic responsive fluid such as magnetic compound fluid (MCF), the effect of electrolytic polymerization on NR-latex such as plastic-type polymer solutions is enhanced, and the thickness of the vulcanized MCF rubber grows in a short time. The present new method of vulcanization of MCF rubber is effective enough that it is widely used in haptic sensors in various engineering applications. In the present report, as mechanical approach for the sensing, by measuring the temperature under electrolytic polymerization, by investigating the electric and dynamic characteristics, and by observing the magnified appearance of the MCF rubber, we clarified the extrinsic effects of many experimental conditions, including magnetic field strength, applied voltage, the electrodes gap, mass concentration, and the ingredients of the MCF. This report is Part 1, to be followed by another sequential report, Part 2, in which other intrinsic effects on the characteristics are dealt with. The experimental conditions used and the results obtained in the present report provide valuable data that will be useful in the making of MCF rubber.

Nano-Precision Polishing of Oxygen-Free Copper Using MCF (Magnetic Compound Fluid) Slurry

Oxygen-free copper (OFC) is a popular material used for molds/dies in injection molding of plastic lens because of its high ductility, strong impact strength and good thermal conductivity. nanoprecision polishing is essential as the final process in its fabrication. For this purpose, a novel polishing method using magnetic compound fluid (MCF) slurry was proposed. In this article, the construction of an experimental rig to realize the proposed method was described at first. Then the effects of process parameters including MCF slurry composition, workpiece oscillation parameter f/Ap-p and clearance Δ between workpiece and MCF carrier on work-surface roughness and material removal were experimentally investigated. As a result, nanoprecision surface finish of OFC was successfully attained by polishing with MCF slurry and the optimum process parameters (f/Ap-p=30 Hz/4mm, Δ=0.6 mm with an MCF slurry (45wt.% of CIP, 12 wt.% of Al2O3 grain, 3 wt.% of α-cellulose, 40 wt.% of MF) for obtaining the smoothest work-surface were determined.

1611 磁気混合流体を用いた円管内面精密加工と流体特性の関係(OS7-3 複雑流体の流動現象・流れの制御・混相流の応用技術)

1611 磁気混合流体を用いた円管内面精密加工と流体特性の関係(OS7-3 複雑流体の流動現象・流れの制御・混相流の応用技術)

711 磁気混合流体を用いた水平円管内面精密加工における工具のトルク特性と加工量の関係(GS3-3 材料加工)

711 磁気混合流体を用いた水平円管内面精密加工における工具のトルク特性と加工量の関係(GS3-3 材料加工)

713 磁気混合流体を用いた石英ガラスの平面研磨の可能性(GS3-3 材料加工)

713 磁気混合流体を用いた石英ガラスの平面研磨の可能性(GS3-3 材料加工)

光学玻璃磁性复合流体抛光液研究

光学玻璃磁性复合流体抛光液研究

712 磁気混合流体を用いたリング状部品内面の精密研磨特性(GS3-3 材料加工)

712 磁気混合流体を用いたリング状部品内面の精密研磨特性(GS3-3 材料加工)

Nano-Precision Polishing of Oxygen-Free Copper Using MCF (Magnetic Compound Fluid) Slurry

Oxygen-free copper (OFC) is a popular material used for molds/dies in injection molding of plastic lens because of its high ductility, strong impact strength and good thermal conductivity. nanoprecision polishing is essential as the final process in its fabrication. For this purpose, a novel polishing method using magnetic compound fluid (MCF) slurry was proposed. In this article, the construction of an experimental rig to realize the proposed method was described at first. Then the effects of process parameters including MCF slurry composition, workpiece oscillation parameter f/Ap-p and clearance Δ between workpiece and MCF carrier on work-surface roughness and material removal were experimentally investigated. As a result, nanoprecision surface finish of OFC was successfully attained by polishing with MCF slurry and the optimum process parameters (f/Ap-p=30 Hz/4mm, Δ=0.6 mm with an MCF slurry (45wt.% of CIP, 12 wt.% of Al2O3 grain, 3 wt.% of α-cellulose, 40 wt.% of MF) for obtaining the smoothest work-surface were determined.

Ultrafine polishing of optical polymer with zirconia-coated carbonyl-iron-particle-based magnetic compound fluid slurry

Optoelectronic devices made using precision polymers must be polished to achieve nanolevel surface roughness for proper device operation. One promising novel finishing technique is magnetic compound fluid (MCF) polishing. An MCF is a mixture of magnetic fluid (MF) and magnetorheological (MR) fluid, both of which use the same solvent. Because conventional carbonyl iron particles (CIPs) used in common water-based MCFs lack the ability to prevent aqueous corrosion, zirconia (ZrO2)-coated CIPs are used in MCFs. For ultrafine polishing of polymethylmethacrylate (PMMA), surface roughness values achieved using ZrO2-coated CIP-based MCF slurries of various compositions were investigated. For comparison, the surface roughness values achieved with conventional non-coated CIP (i.e. HQ CIPs by BASF Japan Ltd.)-based MCF slurry and ZrO2-coated CIP-based MR fluid slurry were examined as well. The results are explained in terms of the status of the used MCF slurries and the generated normal forces during polishing. The use of relatively large abrasive particles (alumina (Al2O3)) in the ZrO2-coated CIP-based MCF slurries did not achieve better surface roughness and higher improvement rates than the conventional HQ CIP-based MCF slurry. Better surface roughness and a higher improvement are attained with MCF slurry than MR fluid slurry, because the magnetite particles within the MCF slurry help distribute the abrasive particles uniformly and stiffen magnetic clusters. In the absence of both Al2O3 abrasives and α-cellulose, better surface roughness is achieved using ZrO2-coated CIP-based MCF slurry; the best surface roughness of Ra 0.913 nm is achieved with a CIP concentration of 70 wt.% at a considerable improvement rate. The ZrO2-coated CIP concentration should be less than a certain value (in the current work, 70 wt.%); otherwise, the MCF slurry will show bad particle dispersion ability and be prone to dryness, which will result in the loss of polishing ability.

A new magnetic compound fluid slurry and its performance in magnetic field-assisted polishing of oxygen-free copper

In nano-precision surface finishing of engineering materials using MCF (magnetic compound fluid) slurry, the water-based MCF slurry is preferable from the viewpoint of the environmental issue and the running cost of cleaning workpiece and equipment. However, the uncoated-CIPs (carbonyl-iron-powders) within the conventional MCF slurry have low ability against aqueous corrosion, leading to the performance deterioration and working life shortening of the conventional MCF slurry. This study proposed a new MCF slurry containing ZrO2-coated CIPs instead of the uncoated CIPs. Its performance in the polishing of oxygen-free copper was compared experimentally with that of the conventional one. The results showed that the work-surface finish polished with the new slurry was in the same level as that with the conventional one when the slurry was used soon after prepared, i.e., the settling time was 0 min; however, as the settling time increased the uncoated-CIPs got rusty, leading to a deterioration in the slurry performance. By contrast, no rust was observed on ZrO2-coated CIPs even the settling time reached several days, indicating the employment of ZrO2-coated CIPs prolonged the working-life of the MCF slurry greatly.

2206 Magnetic field-assisted polishing of miniature V-grooves using MCF(Magnetic Compound Fluid) slurry

Structured optical elements such as Fresnel lenses made of glass or polymers are commonly replicated by hot pressing and/or injection molding using high precision molds with 3D-structured surface like V-grooves. In the fabrication of molds, nano-precision polishing is essential as the final process. In this study, a novel polishing method using magnetic compound fluid (MCF) slurry is proposed. The effects of process parameters including MCF slurry supplying amount, workpiece oscillation parameter and MCF carrier rotational speed on work-surface roughness and form error were experimentally investigated. As a result, nano-precision surface finish of structured surface was successfully attained by polishing with MCF slurry.

0705 Ultra Precision Surface Polishing of Fused Silica Using MCF Wheel Based on Prolongation of Wheel Life

This study proposes a new polishing method using MCF (magnetic compound fluid) slurry for ultra-precision and high-efficiency polishing of fused silica. A semi-fixed abrasive tool called "MCF wheel" was proposed that is in practice produced by putting MCF slurry on the outer surface of ring-shaped permanent magnets. In this paper, method of a certain number of water supplying to MCF wheel in the polishing process is proposed. In the result, prolongation of wheel life is realized because of inhibition of polishing temperature by maintaining of optimal construction of MCF wheel. In addition, ultra precision smooth surface is manufactured.

Nano-precision Polishing of CVD SiC Using MCF (Magnetic Compound Fluid) Slurry

CVD SiC is a perfect material used for molds/dies in hot press molding of glass lens. In its fabrication process, nano?precision polishing is essential finally. For this purpose, a novel polishing method using MCF (Magnetic Compound Fluid) slurry is proposed. In this method, MCF slurry is supplied into a given gap between the workpiece and a MCF slurry carrier, and constrained within the polishing zone by magnetic forces from permanent magnet. In this paper, after an experimental rig used to actually realize the proposed method has been constructed, the fundamental polishing characteristics of CVD SiC such as the effects of process parameters including MCF slurry composition on worksurface roughness were experimentally investigated. As a result, nano?precision surface finish of CVD SiC was successfully attained with MCF slurry and the optimum process parameters for obtaining the smoothest work?surface were determined.

Experimental Research on the Characteristics of the Magnetic Compound Fluid by Grinding Solar Wafers

This paper studies the grinding characteristics of magnetic compound fluid by conducting large amounts of experiments. Magnetic compound fluid (MCF) is formed by mixing abrasive grains, α-cellulose, iron powder and Magnetic-Fluid together according to a certain proportion. The experiments are conducted to test the effect of process parameters (such as different period of time, various speed of main axle and fluctuating magnetic field) on grinding results using Solar wafers. The results showed that the grinding surface of solar wafers is within Ra0.1 after 3 minutes and the microscopic appearance of the surface is flat and free of burns phenomenon.

Ultrafine Polishing of Electroless Nickel–Phosphorus-Plated Mold with Magnetic Compound Fluid Slurry

Electroless nickel–phosphorus (Ni–P)-plated mold for hot press of optical lens must be manufactured to nanolevel surface roughness. The single-crystal diamond turning (SCDT) process is generally used to machine the Ni–P plating layer to attain the required form and ultrafine surface finish. However, this process frequently causes concentrically arranged tool marks to appear on the work surface. In this study, the Ni–P plating layer was polished with magnetic compound fluid (MCF) slurry to remove the tool marks. Two MCF slurries were used, one containing high-quality carbonyl iron particles (CIPs) and alumina (Al2O3) abrasive particles (1 µm), and the other containing CIPs coated with zirconia (ZrO2) abrasive particles (50–100 nm). First, spot polishing without relative motion between the center of the MCF carrier and the workpiece was carried out using both slurries. Then, scanning polishing with the MCF carrier moving along a motion path was carried out using only the MCF slurry containing ZrO2-coated CIPs. Although both slurries removed the SCDT-induced tool marks on the work surface, the MCF slurry containing relatively large Al2O3 abrasive particles left scratches and frequently caused CIPs to be embedded in the Ni–P plating surface, which inversely worsened the work surface roughness. In contrast, the MCF slurry containing relatively small ZrO2 abrasive particles resulted in an improved work surface roughness, without scratches or the embedding of particles. The cross-sectional profile of the polishing spot manifests a characteristic symmetrical W-shape. The dot-shaped scratches were induced at the spot center, and the lengths of these scratches increase with the increase in the distance from the spot center. In scanning polishing, the W-shaped polishing spot moves along the designed scanning path and instantaneous overlapping occurs, which significantly improves the flatness of the Ni–P plating layer from 0.2 to 0.1 µm. In addition, almost all the particles can move relative to the work surface, and the surface finish of the Ni–P plating layer was improved, without scratches or the embedding of particles. The preliminary results show that the MCF polishing is applicable to the nanolevel finishing of soft magnetic materials.

Behavior of Particles in the Process of Magnetic Compound Fluid Polishing of Inner Surface of Micro-Tube with Axial Flow

Behavior of both suspended micrometer-size magnetic particles and micrometer-size nonmagnetic abrasive particles in a micro-tube filled with a magnetic compound fluid is investigated by using discrete particles method based on the simplified Stokesian dynamics in order to reveal the polishing process of inner surface of the tube with an axial flow. Giving the axial flow of the appropriate velocity is effective on performing uniform polishing of the surface in the magnetic compound fluid polishing.

Effects of pressure and shear stress on material removal rate in ultra-fine polishing of optical glass with magnetic compound fluid slurry

Optical glasses used in a range of industrially important optoelectronic devices must be polished to nano-level roughness for proper device operation. Polishing process with magnetic compound fluid slurry (MCF polishing) under a rotary magnetic field is an influential candidate for the method to precisely polish optical glass. MCF slurry has been successfully utilized to polish a variety of materials, ranging from soft optical polymers to hard optical glasses. MCF was developed by mixing a magnetic fluid and a magnetorheological fluid with the same base solvent, and hence includes not only μm-sized iron particles but also nm-sized magnetite particles. To elucidate the behaviour of material removal in MCF polishing, this study measured the normal and shear forces generated in the polishing zone during polishing. From these measurements, the distributions of pressure P and shear stress τ were obtained. The distribution of material removal rate (MRR) was investigated through spot polishing of borosilicate glass. The effects of three process parameters, namely magnet revolution speed, MCF carrier rotational speed and working gap, on pressure P, shear stress τ and the MRR were also investigated. The results revealed that P is higher near the centre of the interacting area (i.e. the polishing spot centre) and the point of maximum shear stress τ appears at about 5mm from the polishing spot centre. All of P, τ and MRR are sensitive to MCF carrier rotational speed and working gap but insensitive to magnet revolution speed. Shear stress is more sensitive to these process parameters than the pressure. Cross-sectional profiles of the polishing spots exhibit a characteristic symmetric W-shape; material removals are minimal at the spot centre and maximal at approximately 8.2–10.2mm from the spot centre depending on the process parameters. MRR is proportional to the MCF carrier rotational speed and is negatively correlated with working gap. An MRR model involving both the pressure and shear stress in MCF polishing is proposed. In the model, MRR is more dominated by shear stress than by pressure.