Magnetic Assisted Abrasion, a New Method for Nano Level Surface Finishing

2010 ◽  
Vol 297-301 ◽  
pp. 402-407 ◽  
Author(s):  
Mehrdad Vahdati ◽  
E. Sadeghinia ◽  
Ali Shokuhfar
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Relative Size ◽  
Considerable Effect ◽  
Surface Finishing ◽  
Work Piece ◽  
Iron Particles ◽  
Abrasive Particles ◽  
Weight Percentage ◽  
Flat Surfaces

A great deal of attention in manufacturing engineering has been focused on finishing operations of hard and brittle materials in recent years. This paper reports an experimental work on the analysis of surface roughness and material removal using design of experiment (DOE) method in magnetic abrasive finishing, (MAF) of flat surfaces. Change in surface roughness and material removal were found to increase with an increase in weight percentage of abrasive particles in magnetic abrasive brush, lubricant volume and decrease in working gap. Also, any decrease in the relative size of the abrasive particles vis-à-vis the iron particles would result into an increase of the surface roughness and decrease in material removal. It was observed that the work piece hardness had no considerable effect on the process results. The optimum parameter levels which lead into the best surface finish and highest material removal were also derived from these experimentations. Optimum levels included weight percentage of abrasive particles of 40%, Lubricant volume of 1 ml, working gap of 3 mm, relative size of abrasive particles vis-à-vis the iron particles of 0.22, and work piece hardness of 82-87 HBN. Disk type test pieces were selected from Al 7075 and their two side surfaces were under experiments. Experiments were made using a milling machine spindle as magnetic pole holder, and its table as fixture holder for work pieces.

Development of a New Plate Polishing Technique with an Instantaneous Tiny-Grinding Wheel Cluster Based on Magnetorheological Effect

2008 ◽  
Vol 53-54 ◽  
pp. 155-160 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Ai Jun Tang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Abrasive Particles ◽  
Magnetorheological Effect ◽  
Material Removal Model ◽  
Mr Effect ◽  
Removal Model

A new plate polishing technique with an instantaneous tiny-grinding wheel cluster based on the magnetorheological (MR) effect is presented in this paper, and some experiments were conducted to prove its effectiveness and applicability. Under certain experimental condition, the material removal rate was improved by a factor of 20.84% as compared with the conventional polishing methods with dissociative abrasive particles, while the surface roughness of the workpiece was not obviously increased. Furthermore, the composite of the MR fluid was optimized to obtain the best polishing performance. On the basis of the experimental results, the material removal model of the new plate polishing technique was presented.

Development of the improved Preston equation for abrasive flow machining of aerofoil structures and components

2018 ◽  
Vol 233 (9) ◽  
pp. 1397-1404 ◽  
Author(s):  
Kai Cheng ◽  
Yizhi Shao ◽  
Mitul Jadva ◽  
Rodrigo Bodenhorst
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Machining Process ◽  
Dynamics Simulation ◽  
Abrasive Machining ◽  
Abrasive Particles ◽  
Abrasive Flow Machining ◽  
Flow Features ◽  
The Media ◽  
Experimental Trials

The paper presents an improved Preston equation, which aims to be part of the industrial application to abrasive flow machining. The equation will aid the engineers to optimise the process for desired surface roughness and edge tolerance characteristics on complex geometries in an intuitive and scientific manner. The methodology presented to derive the equation underpins the fundamental cutting mechanics of abrasive machining or polishing assuming all abrasive particles within the media are spherical as manufacturers defined. Further to derivation, full four factorial experimental trials and computational fluid dynamics simulation are implemented to generate the flow features of media on coupon to evaluate and validate the equation for its competency and accuracy on prediction of material removal. The modified Preston equation can significantly contribute to optimise the abrasive flow machining process, and will advantage the integrated machine design to predict better virtual surface roughness and material removal rates.

Technical Performance of Zirconia-Coated Carbonyl-Iron-Particles Based Magnetic Compound Fluid Slurry in Ultrafine Polishing of PMMA

2012 ◽  
Vol 523-524 ◽  
pp. 161-166 ◽  
Author(s):  
Hui Ru Guo ◽  
Yong Bo Wu ◽  
Ya Guo Li ◽  
Jian Guo Cao ◽  
M. Fujimoto ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Carbonyl Iron ◽  
Particle Dispersion ◽  
Iron Particles ◽  
Time Stability ◽  
Abrasive Particles ◽  
Technical Performance ◽  
Work Surface ◽  
Long Time ◽  
Polishing Force

A kind of zirconia-coated carbonyl-iron-particles (CIPs), which show long-time stability against aqueous, is installed in magnetic compound fluid (MCF) to polish PMMA. Performance (normal polishing force and surface roughness) of zirconia-coated CIP based MCF slurry with different CIP concentrations is investigated. For comparison, the performances of the conventional non-coated CIP (i.e., HQ) based MCF slurry and MRF slurry in which DI-water is employed instead of MF are also examined. In the presence of Al2O3 abrasive particles, the use of zirconia-coated CIP based MCF slurry can not result in better polishing performances compared with conventional HQ CIP based MCF slurry; In the absence of Al2O3 abrasive particles, higher normal polishing force and smoother work-surface were obtained with the zirconia-coated CIP based MCF slurry rather than the MRF slurry; For the zirconia-coated CIP based MCF slurry without abrasive particles, the concentration of zirconia-coated CIP should be less than a certain value (in the current work, 70 wt. %), otherwise MCF slurry shows bad particle dispersion and is easily dried, resulting in the loss of its polishing ability.

Advanced Nano-Finishing Process of SrTiO3 Substrate by Cluster MR-Effect Plate

2013 ◽  
Vol 770 ◽  
pp. 150-154 ◽  
Author(s):  
Zhen Wei Bai ◽  
Qiu Sheng Yan ◽  
Jia Bin Lu
Keyword(s):  
Material Removal ◽  
High Efficiency ◽  
Iron Particles ◽  
Machined Surface ◽  
Abrasive Particles ◽  
Srtio3 Substrate ◽  
Multifunctional Material ◽  
Finishing Process ◽  
Ultra Precision ◽  
Mr Effect

As a new multifunctional material, strontium titanate (SrTiO3) ceramic has a wide application in grain boundary layer capacitor (GBLC) with the microstructure characteristics of semi-conductive crystalline grain and insulated boundary. An ultra-precision nanofishing technique is developed to lap and polish the brittle and thin SrTiO3 substrate with the cluster MR-effect plate where the abrasives are constrained by the cluster MR-effect chains, under the influence of a magnetic field, the carbonyl iron particles (CIPs) and non-magnetic abrasive particles remove material from the surface of workpiece being machined in this paper. Mahr XT20 roughmeter, Keyence VHX-600 and Olympus S4000 microscopes are used to investigate the characteristic of machined surface and the mechanism of material removal. An ultra-smooth planarization surface of SrTiO3 substrate with surface roughness Ra 3.8 nm (Mahr), RMS 0.973 nm (Veeco interferometer) is obtained under a high efficiency. It is found that the pore structures of the sintered substrate would weak the machinability of SrTiO3 and influence the further improvement of surface quality.

scholarly journals New Droplet Removal Polishing Method for Diamond-Like Carbon with Carbon Fiber Brush

2020 ◽  
Vol 14 (2) ◽  
pp. 190-199
Author(s):  
Motoyuki Murashima ◽  
◽  
Yusuke Imaizumi ◽  
Noritsugu Umehara ◽  
Takayuki Tokoroyama
Keyword(s):  
Surface Roughness ◽  
Carbon Fiber ◽  
Carbonaceous Material ◽  
Surface Finishing ◽  
Polished Surface ◽  
Diamond Like Carbon ◽  
Average Roughness ◽  
Arithmetic Average ◽  
Flat Surfaces ◽  
Dlc Coating

In this paper, we propose a new polishing method for diamond-like carbon (DLC) coatings using a carbon fiber brush (CFB). Surface finishing is an important process for DLC coating applications. A lapping process is widely used for attaining tetrahedral amorphous carbon (ta-C) coatings, which are a type of DLC coating containing many droplets, to obtain fine flat surfaces. The lapping process removes protuberant parts of droplets rather than the entire droplet. In this paper, we propose a new polish brush material made of carbon fiber, called CFB. Carbon fiber has both mechanical strength due to its hard carbonaceous material and flexibility due to its fiber structure. In polishing tests, CFB removed droplets from ta-C coatings and the removal effect increased with the shortening of the brush length. The surface profiles of the polished surfaces indicated that a shorter brush length yielded deep scratch marks on ta-C surfaces. Consequently, the arithmetic average surface roughness of the polished ta-C surfaces, Sa, had almost the same value as that of a non-polished surface. Here, we show the ability of CFB to remove the droplets without an increase in the surface roughness. The CFB with the longest brush length in the present study (12 mm) showed a ten-point average roughness SZJIS= 75 nm and Sa= 4.7 nm, which were 59% and 22% lower than those of the non-polished surface, respectively. Furthermore, the longest CFB removed the entire droplets whereas a shorter CFB merely removed the protuberant part of the droplets. The result indicates that CFB polishing can remove entire droplets, which result in abrasive wear or deterioration. From other polishing tests, the optimum polishing distance was determined. Shorter polishing distances could not remove droplets sufficiently whereas longer polishing distances caused deep scratches on ta-C surfaces due to the material transferred to the CFB. Accordingly, the polishing distance of 600 m showed the best surface finishing with SZJIN= 25 nm and Ra= 0.43 nm, which were 86% lower than and similar to those of the non-polished ta-C surface, respectively.

scholarly journals Towards the Determination of Machining Allowances and Surface Roughness of 3D-Printed Parts Subjected to Abrasive Flow Machining

2021 ◽  
Vol 5 (4) ◽  
pp. 111
Author(s):  
Mykhailo Samoilenko ◽  
Greg Lanik ◽  
Vladimir Brailovski
Keyword(s):  
Surface Roughness ◽  
Computer Aided Design ◽  
Material Removal ◽  
Orientation Dependence ◽  
Surface Finishing ◽  
Abrasive Medium ◽  
Abrasive Flow Machining ◽  
Planar Surfaces ◽  
Numerical Tool

Abrasive flow machining (AFM) is considered as one of the best-suited techniques for surface finishing of laser powder bed fused (LPBF) parts. In order to determine the AFM-related allowances to be applied during the design of LPBF parts, a numerical tool allowing to predict the material removal and the surface roughness of these parts as a function of the AFM conditions is developed. This numerical tool is based on the use of a simplified viscoelastic non-Newtonian medium flow model and calibrated using specially designed artifacts containing four planar surfaces with different surface roughnesses to account for the build orientation dependence of the surface finish of LPBF parts. The model calibration allows the determination of the abrasive medium-polished part slip coefficient, the fluid relaxation time and the abrading (Preston) coefficient, as well as of the surface roughness evolution as a function of the material removal. For model validation, LPBF parts printed from the same material as the calibration artifacts, but having a relatively complex tubular geometry, were polished using the same abrasive medium. The average discrepancy between the calculated and experimental material removal and surface roughness values did not exceed 25%, which is deemed acceptable for real-case applications. A practical application of the numerical tool developed was demonstrated using the predicted AFM allowances for the generation of a compensated computer-aided design (CAD) model of the part to be printed.

scholarly journals Effect of the Lapping Platen Groove Density on the Characteristics of Microabrasive-Based Lapping

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 775
Author(s):  
Taekyung Lee ◽  
Haedo Jeong ◽  
Sangjik Lee ◽  
Doyeon Kim ◽  
Hyoungjae Kim
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Material Removal ◽  
Removal Rate ◽  
High Surface ◽  
Abrasive Particle ◽  
Process Conditions ◽  
Abrasive Particles ◽  
Oil Film ◽  
Process Characteristics

Microabrasive-based lapping is widely used in the manufacturing of single-crystal substrates such as sapphire, SiC, and GaN. Although many studies have been conducted to improve the lapping process characteristics, most of them focused on process conditions or consumables. In this study, the effect of the lapping platen groove density on the lapping characteristics was studied using a sapphire substrate. Groove density was defined as the ratio of groove width to groove pitch, and the displacement of the lapping head was measured to calculate the oil film thickness. It was confirmed that, for groove densities below 0.30, hydroplaning occurs when the oil film thickness increases. When the oil film thickness is larger than the abrasive particle size, the material removal rate is low because the abrasive does not participate in the lapping process. When the oil film was developed, the experimental results showed a high surface roughness and poor flatness of the substrate, as only large abrasive particles participated in the lapping process. Therefore, to improve the lapping characteristics, it is important to reduce the groove density by reducing the groove pitch, which prevents the development of the oil film.

Design and Fabrication of Abrasive Jet Machine (AJM) & Analyzing its Performance

2019 ◽  
Vol 1 (1) ◽  
pp. 49-55
Author(s):  
Mahesh Reddy Vaddhi ◽  
M. Leela Ramesh ◽  
B Malsoor ◽  
Sai Teja
Keyword(s):  
Material Removal ◽  
High Speed ◽  
Brittle Materials ◽  
Glass Ceramics ◽  
Machining Process ◽  
Work Piece ◽  
Abrasive Particles ◽  
High Speed Stream ◽  
Abrasive Jet Machining ◽  
Gas Medium

Abrasive Jet Machining (AJM) is the process of material removal from a work piece by the application of a high speed stream of abrasive particles carried in a gas medium from a nozzle. The material removal process is mainly by erosion. The AJM can principally be wont to cut shapes in arduous and brittle materials like glass, ceramics etc. In this concept, a model of the Abrasive Jet Machine is proposed to design by taking into consideration of commercially available components. Care will be taken to use less fabricated components rather than directly procuring them, because, the lack of accuracy in fabricated components would lead to a diminished performance of the machine. To analyse its performance, Drilling of glass sheets with different abrasives and different nozzles will be carried out by Abrasive Jet Machining process (AJM) in order to determine its machinability.

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

2008 ◽  
Vol 389-390 ◽  
pp. 187-192
Author(s):  
Yong Bo Wu ◽  
Kunio Shimada
Keyword(s):  
Surface Roughness ◽  
Liquid Nitrogen ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Abrasive Particles ◽  
Water Based ◽  
Quartz Wafer ◽  
Polishing Tool

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%.

scholarly journals Investigation on Polishing of Zirconia Ceramics Using Magnetic Compound Fluid: Relationship Between Material Removal and Surface Roughness

2021 ◽  
Vol 15 (1) ◽  
pp. 17-23
Author(s):  
Ming Feng ◽  
Youliang Wang ◽  
Yongbo Wu ◽  
◽  
◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Material Removal ◽  
Surface Profile ◽  
Automotive Electronics ◽  
Iron Particles ◽  
Zirconia Ceramics ◽  
New Energy ◽  
Polishing Force ◽  
Biomedical Fields

Zirconia ceramics have excellent applicability in the aerospace, defense, new energy, automotive, electronics, and biomedical fields. However, few investigations have been conducted on the high-precision polishing of zirconia ceramics. In this work, a polishing method using a magnetic compound fluid slurry is proposed. First, the principle and the constructed experimental setup were presented. Then, the experiments were performed that characterized the surface profile after polishing, the effect of the working gap, and the effect of the concentration of carbonyl iron particles (CIPs) on the material removal and surface quality. The results showed that the material removal ability correlated positively with the surface roughness; the smallest working gap (0.5 mm) induced greater material removal ability and better surface roughness; higher CIP concentration enabled a higher polishing force to obtain higher material removal and better surface quality. The polishing results show that surface roughness Rz of 55 nm was obtained at the surfaces of zirconia ceramics, confirming that the proposed method has the potential for polishing of zirconia ceramics.

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