Magnetic Compound Fluid Polishing Research Articles

Synthesis and characterization of Fe3O4@SiO2 core-shell nanoparticles for mirror and efficient magnetic compound fluid polishing of TC4 titanium alloy

To fully investigate the polishing performance of the Fe3O4@SiO2 core–shell abrasive for TC4 titanium alloy plate and solve the problem of uneven distribution of abrasive particles in magnetic compound fluid polishing (MCFP) and obtain ultra-smooth titanium alloy surface. In this paper, the functional Fe3O4@SiO2 core–shell abrasives were prepared and characterized by XRD, FTIR, VSM and TEM to demonstrate the successful encapsulation of SiO2 in Fe3O4 first. Second, a new polishing device was built to perform polishing experiments. Four different fractions of Magnetic compound fluid (MCF) were configured and utilized in polishing experiments for MCFP of TC4 titanium alloy to verify the polishing properties. Finally, the contact model between abrasive particles and workpiece is established and the material removal mechanism is discussed. The results show that SiO2 was successfully coated on Fe3O4. The polishing results show that the MCF containing the core–shell structure had the best polishing effect. The surface roughness Ra decreased from 0.201 μm to 0.025 μm after 20 min of polishing. The surface roughness of TC4 titanium alloy with an initial roughness Sa of 0.248 μm is reduced to 0.023 μm after polishing by Fe3O4@SiO2 core–shell abrasive. It is shown that the application of core–shell abrasive to process titanium alloys can obtain smooth and defect-free surfaces with good polishing performance. The surface quality of titanium alloy can be improved effectively by using core–shell abrasive, and a new idea for polishing titanium alloy is proposed. This study plays an important role in solving the problem of uneven particle distribution in MCFP. These results pave the way for further research into the application of core–shell abrasives in precision machining and expand the application scope of particles with core–shell structure.

Investigation on Polishing the Concave Surface of Zirconia Ceramics with Magnetic Compound Fluid Enhanced by Hydration Reaction

Zirconia ceramics are prominent engineering materials and are widely used in computers, consumer electronics, and the fifth-generation communication industry. However, zirconia ceramics are a typical hard-to-cut material, and the product structures are more complex as the demanding on the industry increases. In this case, the polishing efficiency should be improved for meeting these requirements. To overcome the problem of polishing concave surfaces of zirconia ceramics, a small polishing tool with a magnetic compound fluid (MCF) was invented. The effect of the polishing parameters on the surface roughness and material removal rate was analyzed by an L9(33) orthogonal experiment. The weight ratio of the parameters was also studied based on the experimental results. With the combination of chemical and mechanical functions, the polishing characteristics were further examined. Based on the soaking experiments, the material removal mechanism is discussed. The results are as follows: (1) the optimal polishing parameters were the revolution speed of the MCF carrier nc of 400 rpm, the working gap h of 0.1 mm, the CIP size D of 5 μm for better surface roughness, the revolution speed of the MCF carrier nc of 400 rpm, the working gap h of 0.1 mm, and the CIP size D of 7 μm for a higher material removal rate. The impact degrees on surface roughness and material removal rate were a revolution speed of the MCF carrier of 54% > working gap of 31%> CIP size of 15% and working gap of 40% > revolution speed of the MCF carrier of 32% > and CIP size of 18%, respectively. (2) Surface roughness was rapidly reduced in the first 20 min and tended to be stable in the last 10 min of polishing. A circular polished area was observed on the flat workpiece for studying the typical material removal curve, and the deepest point was found at the fringe of the material removal curve. The concave workpiece was polished successfully, and the best surface roughness Ra reached 1 nm and 1.2 nm. (3) A pH = 10 with a sodium hydroxide (NaOH) solution has a greater performance in hardness reduction. The chemical and mechanical functions were combined to remove material to enhance the polishing efficiency. All in all, the proposed polishing method with a combination of a small MCF polishing tool and hydration reaction was effective for polishing zirconia ceramics.

A Novel Polishing Method for Extending the Service Life of Magnetic Compound Fluid

Magnetic field-assisted magnetic compound fluid (MCF) ultra-precision machining technology is regarded as an effective method to obtain a smooth surface. However, due to the evaporation and splashing of water in the polishing fluid during processing, the service life of the MCF slurry is reduced. This paper presents a material removal model for MCF polishing, and a novel experimental apparatus is proposed to extend the service life by supplying MCF components into the MCF slurry. Firstly, in order to obtain the ideal polishing tool, the appearance morphologies and the formation process of the MCF slurry were observed by an industrial camera. On this basis, the optimum parameters were determined by multi-factor and multi-level orthogonal experiments. Finally, the investigation of the MCF service life was carried out under the optimal processing parameters. The main findings are summarized as follows. (1) Excellent MCF polishing tools are obtained when the eccentric distance r is 4 mm and the MCF slurry supply V is 1 mL. (2) When the eccentric distance increases from 2 mm to 4 mm, the forming time of the MCF tool decreases sharply, but when the eccentricity exceeds 4 mm, the decreasing trend becomes slow. The molding time grows steadily as the supply is increased. (3) When the machining gap Δ, the MCF carrier speed nc, the eccentricity r, and the revolution speed of magnetic nm are 1 mm, 500 rpm, 4 mm, and 600 rpm, respectively, the ideal machining effect can be obtained. (4) It could be proven that the polishing device is feasible to extend the service time of the MCF slurry by adding MCF components.

Development of Ultrasonic Vibration-Assisted Magnetic Compound Fluid (MCF) Polishing Technology

This study investigates the development of an ultrasonic vibration-assisted magnetic compound fluid (MCF) polishing technology for final polishing. The fabrication of an experimental apparatus entails an ultrasonic polishing unit, and the experimental investigation of its performance in surface polishing is described. In addition, ultrasonic vibration-assisted MCF polishing under different applied methods of ultrasonic vibration is studied. The experimental results indicate that applying ultrasonic vibration to the workpiece improves the surface roughness and material removal rate when the ultrasonic vibrations are changed. In addition, across the range of polishing conditions employed in this study, the precision surface roughness and high material removal rate can be easily obtained on the acrylic plate by applying an elliptical vibration to the ultrasonic vibration.

Feasibility Study on the Precision Polishing of Zirconia Ceramics with Magnetic Compound Fluid (MCF) Slurry Under the Assistance of Dielectrophoresis Effect

In this work, a new polishing method for zirconia ceramics was firstly proposed, which combined dielec-trophoresis effect with magnetic compound fluid polishing. A key experimental device was designed and constructed, and the influence behavior of dielectrophoresis phenomenon on the polishing efficiency, surface roughness and glossiness of zirconia ceramic workpiece were investigated. Also, the effects of voltage, electrode shape and electric field parameters on the polishing results were deeply discussed. The results showed that when the magnetic field was stronger, the polishing efficiency would become higher, while the surface quality of the workpiece getting worse. And the glossiness was positively correlated with the surface roughness. Moreover, the smaller the electrode shape and the larger the electric field gradient caused the better dielectrophoresis-assisted effect. It was indicated that when the electrode shape was a circle with a diameter of 20 mm and the voltage was 1500 V, the material removal efficiency was improved by 36.4% while ensuring the surface quality of zirconia ceramics.

Effect of the components of Magnetic Compound Fluid (MCF) slurry on polishing characteristics in aspheric-surface finishing with the doughnut-shaped MCF tool

For the aspheric optical surface finished with a doughnut-shaped MCF (magnetic compound fluid) polishing tool, the performance of the polishing tool depends mainly on the properties of the MCF slurry. Therefore, understanding the effect of each MCF slurry component on the polishing characteristics is crucial to developing novel polishing techniques. In this paper, the polishing principle was depicted and the corresponding polishing jig was constructed with a six-degree-of-freedom manipulator. The conical surfaces, which were considered as special aspheric surfaces, were experimentally polished under proper polishing conditions to examine the effects of the carbonyl iron particles (CIPs) concentration and the sizes of the abrasive particles (APs) on the polishing ability to remove material/tool marks and improve work surface qualities. Theoretical analyses were also performed to gain a more comprehensive understanding of the behaviors of CIPs and APs in the magnetic field. The results were shown as follows: (1) The CIPs concentration affected positively the magnetization of the MCF slurry, leading to better performance in the removal rate of material/tool marks when a higher CIPs concentration of was applied. The best surface quality was attained with a CIPs concentration of 45 wt%. (2) Larger APs were beneficial for obtaining higher removal rates of material/tool marks. The APs with 1 μm in diameter were preferred for achieving a better surface quality. (3) Ferric clusters were formed along the magnetic line of force and their orientations changed periodically to stir the APs with the magnet revolution. (4) The Aps, at a given working gap, can squeeze the work-surface. The squeezing action was much more intense when larger APs and the MCF slurry with a higher magnetization were employed. (5) The material removal model suggested that the material was removed due to the APs and the relative motion between the work-surface and APs.

Estimation of Energy Savings When Adopting Ultrasonic Vibration-Assisted Magnetic Compound Fluid Polishing

Reducing energy use is a major consideration in green manufacturing. Ultrasonic vibration has the advantage of improving machining performance. This work presents an experimental investigation on magnetic compound fluid (MCF) polishing with and without ultrasonic vibration and estimates reductions in polishing energy consumption and surface roughness due to ultrasonic vibration during the machining process. A series of ultrasonic vibration-assisted MCF polishing (UVAMP) tests was carried out for brass H62, and the normal and tangential polishing forces, surface roughness and material removal rate of the traditional MCF polishing (MP) and UVAMP of brass were investigated for various machining parameters. The polishing energy consumptions during traditional MCF polishing and UVAMP were calculated and analyzed from the perspective of the energy of the polishing process. Results indicate that the use of UVAMP considerably reduces energy consumption and surface roughness during the polishing of brass. The adoption of UVAMP therefore has the potential to improve the efficiency and quality of polishing processes and offers a practical solution for the greener manufacturing of brass.

Effects of Water Supply Using Ultrasonic Atomization on the Working Life of MCF Slurry in MCF Polishing

The magnetic compound fluid (MCF) polishing process is a precision finishing method that has been applied to a large variety of materials, from soft optical polymers to hard ceramics. The purpose of this study is to extend the working life of MCF slurry. In this paper, we focus on the drying phenomenon of MCF slurry during polishing, and we develop a new water supply system that uses an ultrasonic atomization mechanism. This system can moisturize the MCF polishing area locally. Polishing experiments involving supplying water to MCF slurry are carried out, and extending the working life of MCF slurry is discussed.

Fundamental Investigation on the Polishing Aspheric Elements with Doughnut-Shaped MCF Slurry

Previous researches have confirmed that MCF (magnetic compound fluid) slurry shows outstanding performance in the nanoprecision polishing of flat surfaces and V-grooves. However, no investigations have been conducted on the polishing of aspheric surfaces using MCF slurry. In this work, a novel method employing a doughnut-shaped MCF polishing tool and a 6-DOF manipulator has been proposed for the aspheric surface polishing. The time consumption for forming stable polishing tool and its final appearance are investigated. Flat aluminum alloy workpieces that can be considered as a kind of aspheric elements with infinite curve radius were adopted in the investigation of the polished forces under variable parameters. As a typical experimental result, with MCF3 slurry, 2.5ml volume of supplied slurry and work gap 3.5 mm, the surface roughness Ra decreases from 125nm to almost 10nm after 90 min polishing, confirming that the proposed method has the potential to polish aspheric surfaces.

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.

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.

C02 磁気混合流体(MCF)スラリーによるNi-Pめっきの超精密研磨(OS10 班磨技術(1))

Nickel phosphorus (Ni-P) plating on the optical lens mold was polished with magnetic compound fluid (MCF) slurry. Two typtes of MCF slurry were applied. MCF1 slurry is an HQ carbonyl-iron-particles (CIPs)and alumina abrasive particles based one while MCF2 slurry is a new zirconia-coated CIPs based one. The spiral shaped cutting marks on the Ni-P plating were eliminated by both the MCF slurries. As alumina abrasive particles in MCF1 are a little larger and harder than zirconia abrasives in MCF2, scratches and CIPs embedding were caused and it is difficult to further improve the surface finish. In contrast, no scratches and CIPs embedding were induced with the new zirconia-coated CIPs based MCF slurry and improvement for the surface roughness of rms and Ra was achieved. It is also found that polishing trace in both X-axis and Y-axis directions is good to enhance the surface finish and the flatness of the sample. The preliminary results show that MCF polishing is applicable for the nano-level polishing of soft magnetic material.

The Detailed Performance of MCF Polishing Liquid in Nano-Precision Surface Treatment of Acrylic Resin

This paper deals with the experimental investigation on the detailed performance of MCF (magnetic compound fluid) polishing liquid (MPL) in nano-precision surface treatment of acrylic resin that is essentially required for producing the model in the process of developing an inaugural mechanical system. The MPL is produced in practice by mixing iron powder, abrasive particle and -cellulose fiber into a MF (magnetic fluid), and hence a kind of functional fluid reacting to magnetic fields. Following the previous works confirming the performance of MPL in the surface finishing of acrylic resin, in this work a series of experiments were conducted to reveal how the process parameters affect the machining characteristics in details in order to establish the new technique. The results showed that a mirror surface can be easily obtained once the process parameters have been set up optimally.

Fundamental performance of magnetic compound fluid (MCF) polishing tool in metal surface finishing

This paper proposes a new finishing method for metal surface using magnetic compound fluid (MCF) polishing tool that is produced by semi-solidifying MCF containing abrasive particles. The semi-solidification of MCF is carried out under a compression pressure with an applied magnetic field. MCF is a mixture of kerosene-based magnetic fluid (MF) containing 10 nm-size magnetite (Fe3O4), micro-size iron (Fe) powder and α-cellulose fibre. Microscopic observation of MCF polishing tools prepared at different compositions and the MCF shear strengths together with fundamental performances in constant-contact-force polishing were experimentally investigated. A simple empirical equation to evaluate material removal using MCF polishing tool is also discussed. The experimental results indicated that MCF polishing tools prepared at different compositions influences the tool shear strength and subsequently polishing tool that possess high shear strength showed a better improvement in metal-surface finishing.

Quartz Wafer Machining Using MCF (Magnetic Compound Fluid) Polishing Liquid Frozen with Liquid Nitrogen

This paper deals with the machining of quartz wafers using an MCF (Magnetic Compound Fluid) polishing liquid, frozen with liquid nitrogen. This type of polishing liquid is composed of water-based MF (Magnetic Fluid), iron powder, abrasive particle and α-cellulose, and consequently reacting to magnetic fields. Experiments of polishing quartz wafers using the MCF method were carried out on a previously developed apparatus. The results show that an MCF polishing liquid, frozen with liquid nitrogen, has greater material removal capability than one that has not been frozen. A frozen MCF polishing liquid containing larger abrasive particles yields a higher material removal rate, however the surface roughness deteriorates. The highest material removal rate and the best surface roughness were obtained when the percentage of water, in the frozen MCF polishing tool, was 34.7%.

Fundamental performance of magnetic compound fluid polishing liquid in contact-free polishing of metal surface

Abstract The present work proposed a new contact-free surface finishing method for metal surface with micro-3D structure utilizing magnetic compound fluid (MCF) polishing liquid, a functional liquid composed of nano-sized magnetite particle, micro-sized iron particle, several 10 μm-sized α-cellulose fiber, and sub-micro-sized abrasive particle that reacts to the magnetic field. As a step to completely develop the technique, this article deals with the experimental investigation on the effects of the magnetic field applying, the abrasive particle size, the blend ratios of abrasive particle and the iron powder on the polishing characteristics (i.e., surface roughness and material removal) of stainless steel (SUS304) specimen. The obtained results showed that (1) when the magnetic field is applied only by installing the upper magnet, a better work surface is obtained but the material removal becomes smaller compared with that both the upper and lower magnets are installed; (2) a better surface and a larger material removal are obtained when larger-sized abrasive particles are used for polishing; (3) the respective optimum concentrations of the abrasive particle and the iron powder within the MCF polishing liquid exist in terms of the polishing characteristics; in the current experimental conditions, the optimum values for the concentrations of abrasive and iron powder were 20 and 20–40 wt.%, respectively.