scholarly journals Investigation on Feasibility of Polishing Concave Surfaces Using Magnetic Compound Fluid Slurry

2021 ◽  
Vol 15 (1) ◽  
pp. 34-40
Author(s):  
Ming Feng ◽  
Yingrui Xie ◽  
Leran Chen ◽  
Yongbo Wu ◽  
◽  
...  
Keyword(s):  
Surface Quality ◽  
Flat Surface ◽  
Surface Profile ◽  
High Standard ◽  
Concave Surface ◽  
Smart Devices ◽  
Polishing Process ◽  
First Time ◽  
The Magnetic Field

Concave surfaces are widely used in the shells of smart devices, such as smartphones, watches, or molds. The quality of the concave surface is important in enhancing the value of these products. In order to improve the surface quality, the polishing process is crucial for removing defects on the concave surface and for smoothing the surface after machining or grinding. Magnetic assisted polishing is a promising method that can be used to meet the high standard of surface quality required. In this work, as a promising smart material in nano-precision polishing, magnetic compound fluid (MCF) slurry was used for the first time to polish a concave surface with a magnet that is magnetized in the radial direction. A simulation of the magnetic field distribution was performed in advance to clarify the polishing characteristics in theory. Subsequently, a polishing experiment was conducted to investigate the feasibility of this polishing method. Finally, the results demonstrated that both a curved surface and a flat surface could be polished successfully. Furthermore, the nano-precision PV value (the distance from the peak to the valley in the surface profile) and the surface roughness Ra were obtained for both areas, and this method was demonstrated to be capable of polishing concave surfaces and worthy of further research.

A Study on Surface Quality of GaN with CMP Polishing Process

2011 ◽  
Vol 291-294 ◽  
pp. 1764-1767
Author(s):  
Wei Li ◽  
Ming Ming Ma ◽  
Bin Hu
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Gallium Nitride ◽  
Surface Quality ◽  
Chemical Reaction ◽  
Experimental Result ◽  
Precision Machining ◽  
Polishing Process

This paper introduced a polishing process for planarization of gallium nitride (GaN) wafer by polishing slurry that is made up by the chemical reaction with H2O2 solution and iron. Some different polishing parameters in the polishing process has been analyzed, which affect the surface quality of wafers, such as slurry particle size, polishing times, polishing slurry etc., and trying to improve the polishing process by optimization of the polishing parameters. The experimental result showed that this polishing method has an effect on the surface quality of GaN wafers, finally, the efficient and precision machining with surface roughness of GaN wafers of Ra0.81 nm has been gained by the CMP polishing process.

Influence of Various Conditions on Quality of Burnished Surface in Developed Roller Burnishing with Active Rotary Tool

2018 ◽  
Vol 12 (6) ◽  
pp. 921-929 ◽  
Author(s):  
Masato Okada ◽  
Makoto Shinke ◽  
Masaaki Otsu ◽  
Takuya Miura ◽  
Kuniaki Dohda ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Surface Profile ◽  
External Appearance ◽  
Roller Burnishing ◽  
Sliding Direction ◽  
Rotary Tool ◽  
Superior Surface ◽  
Cylindrical Workpiece

Burnishing characteristics of a newly developed roller burnishing method were developed. The developed method can effectively control the sliding direction between the roller and a cylindrical workpiece by inclining the roller axis with respect to the workpiece axis. The outer surface of a round aluminum alloy bar was targeted. The influence of burnishing conditions on burnished-surface quality was investigated, and surface quality was evaluated based primarily on the surface roughness, surface profile, and external appearance. As observed, the burnished-surface quality was strongly influenced by the pressing force, roller-inclination angle, and number of tool passes. A superior surface quality could be realized by increasing the number of tool passes.

Super Polishing Behaviour Investigation of Stainless Steel Optical Lens Moulding Inserts

2009 ◽  
Vol 404 ◽  
pp. 97-102
Author(s):  
Kui Liu ◽  
S.T. Ng ◽  
K.C. Shaw ◽  
G.C. Lim
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Quality ◽  
Optical Quality ◽  
Polishing Process ◽  
Optical Lens ◽  
Fine Diamond ◽  
Diamond Paste ◽  
Quality Surface

Super polishing experiments were carried out to investigate the effects of polishing parameters on surface quality of stainless steel lens moulding inserts, and to optimize polishing conditions. Experimental results indicated that optical quality surface of stainless steel lens moulding inserts can be achieved through a two-step polishing process: fast polishing with a soft wood head and coarse diamond paste, and fine polishing with a nylon-covered steel ball head and fine diamond paste. A diameter of 20 mm stainless steel lens moulding insert with a surface roughness Ra of 7.6 nm has been successfully achieved using the two-step super polishing process.

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

2021 ◽  
Vol 13 (5) ◽  
pp. 874-882
Author(s):  
Lijun Wang ◽  
Yongbo Wu
Keyword(s):  
Surface Roughness ◽  
Electric Field ◽  
Surface Quality ◽  
Zirconia Ceramic ◽  
Zirconia Ceramics ◽  
Electrode Shape ◽  
Polishing Efficiency ◽  
The Magnetic Field ◽  
Influence Behavior

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.

Method for assessing the surface quality of copper cathodes

1970 ◽  
Author(s):  
E.V. Shulga ◽  
A.I. Yurev ◽  
M.I. Bazanov
Keyword(s):  
Surface Quality ◽  
Cathode Surface ◽  
Special Technique ◽  
Practical Application ◽  
European Standard ◽  
Cathode Copper ◽  
Current Production ◽  
Polar Division ◽  
First Time

One of the criteria for the quality of high-purity copper, which makes it possible to evaluate its mechanical properties and, accordingly, its suitability for use by consumers, is the spiral elongation number which, in accordance with the requirements of the European Standard EN 12893, must be at least 400 mm.  In order to stabilize spiral elongation number at the required level, an estimate is made of its distribution along the cathode web.  Experimentally obtained results, processed using mathematical statistics methods, showed significant discrepancies between the spiral elongation values in the central and other parts of the cathode (upper, lower, side), which indicates an uneven distribution of the spiral elongation number along the cathode web.  It was found that in order to form a representative analytical sample under cathode copper cathode production of the Polar Division of MMC «Norilsk Nickel», cathode testing should be performed using methods that include all areas of the cathode web, including edges and ears. To determine the dependence of the spiral elongation number on the surface quality of copper cathodes, a special technique has been developed, based on the detection of the most frequently encountered defects in the surface of the cathode web, which is assigned a certain numerical value in accordance with the ranking results.  The proposed scoring system for the quality of cathodes in appearance allowed us to establish for the first time that stabilization of the spiral elongation number at a level of at least 400 mm is possible if the defectiveness of the cathode surface does not exceed 17 points per bath.  The technique has found practical application for assessing the surface quality of copper cathodes under current production conditions. 

scholarly journals Выглаживание поверхности антимонида галлия

2020 ◽  
Vol 46 (23) ◽  
pp. 48
Author(s):  
Р.В. Левин ◽  
И.В. Федоров ◽  
А.С. Власов ◽  
П.Н. Брунков ◽  
Б.В. Пушный
Keyword(s):  
Surface Quality ◽  
Annealing Time ◽  
Smooth Surface ◽  
Annealing Conditions ◽  
First Time

For the first time, the results of a study of the conditions for obtaining an atomically smooth surface of GaSb substrates are presented. It is shown experimentally that it is possible to improve the surface quality of the samples by changing the annealing conditions. The lowest obtained roughness of 1.27 nm was obtained at an annealing time of 16 minutes at a temperature of 650°C in the flow of TMSb and H2.

New Ways at the Fine Grinding

2013 ◽  
Vol 581 ◽  
pp. 255-260 ◽  
Author(s):  
Martin Novák
Keyword(s):  
Surface Quality ◽  
Traditional Approach ◽  
Surface Profile ◽  
Ground Surface ◽  
Cutting Parameters ◽  
Grinding Wheel ◽  
Roughness Parameters ◽  
Machined Parts ◽  
Machining Operations

The traditional approach to grinding is to operate within the limits of surface quality. The requirements for surface quality in grinding are higher than those in other common machining operations such as turning and milling. The surface quality of machined parts is very important for precise production and assembly. When we focus on roughness parameters after grinding, we can establish the limits of these parameters for typical grain materials: Al2O3, SiC, CBN, SG and others. Increasing demands on accuracy and quality of production leads to research concerned with the properties of these materials and the surface quality after grinding. This paper shows new possibilities for the ground surface with focus on surface roughness obtained under varying combinations of cutting conditions. The influence of the grinding wheel, cutting parameters and coolant on higher surface quality is assessed by roughness parameters Ra, Rz, Rt and the Material portion of a surface profile. These high-precision ground surfaces are shown to have a Nanometres (10-9) unit topography demonstrating that the process is able to replace other finishing technologies such as superfinishing or honing.

Large-Area Homoepitaxial Growth of Low-Doped Thick Epilayers for Power Devices with VBR > 4 kV

2009 ◽  
Vol 615-617 ◽  
pp. 77-80 ◽  
Author(s):  
Bernd Thomas ◽  
Christian Hecht ◽  
Birgit Kallinger
Keyword(s):  
Layer Thickness ◽  
Surface Quality ◽  
Doping Concentration ◽  
Epitaxial Layers ◽  
Power Devices ◽  
Large Area ◽  
Homoepitaxial Growth ◽  
Different Types ◽  
First Time

In this paper we present results on the growth of low-doped thick epitaxial layers on 4° off-oriented 4H-SiC using a commercially available hot-wall multi-wafer CVD system. For the first time we show results of a low-doped full-loaded 73” run on 4° off-oriented substrates with a layer thickness of more than 70 µm. The target doping concentration of 1.2×1015 cm-3 is suitable for blocking voltages > 6 kV. Results on doping, thickness and wafer-to-wafer homogeneities are shown. The surface quality of the grown layers was characterized by AFM. The density of different types of dislocations was determined by Defect Selective Etching.

The Polishing Process of Cylindrical Rollers by Using a Double-Side Lapping Machine

2013 ◽  
Vol 589-590 ◽  
pp. 447-450 ◽  
Author(s):  
Wen Hua Zhou ◽  
Wei Feng Yao ◽  
Ming Feng ◽  
Bing Hai Lv ◽  
Qian Fa Deng
Keyword(s):  
Surface Quality ◽  
Cylindrical Surface ◽  
Smooth Surface ◽  
Great Influence ◽  
Working Life ◽  
Geometric Accuracy ◽  
Polishing Process ◽  
Rolling Bearings ◽  
Lapping Machine

The surface quality of cylindrical rollers has a great influence on the working life of rolling bearings. In the paper, double-side lapping machine and flannelette pads are applied to polish the cylindrical surface of rollers. After 20 min polishing, rollers with smooth surface are obtained and the roundness of the rollers have a improvement of about 0.3 μm, which means that the polishing process based on double-side lapping method can effectively improve the surface quality and geometric accuracy of cylindrical rollers.

scholarly journals METHOD FOR ASSESSING SURFACE QUALITY OF COPPER CATHODES

2019 ◽  
Vol 62 (2) ◽  
pp. 53-58
Author(s):  
Elena V. Shulga ◽  
Aleksandr I. Yurev ◽  
Mikhail I. Bazanov
Keyword(s):  
Surface Quality ◽  
Quantitative Estimation ◽  
Copper Production ◽  
Special Technique ◽  
Vertical Strip ◽  
Current Production ◽  
Electrolysis Bath ◽  
Polar Division ◽  
First Time

In order to stabilize spiral elongation number at the required level (in accordance with the requirements of the European standard EN 12893 not less than 400 mm) the assessment of its distribution on the cathode sheet was carried out. The experimentally obtained results, processed using methods of mathematical statistics, showed significant discrepancies between the values of spiral elongation in the central and other parts of the cathode (upper, lower, side), which indicates an uneven distribution of the spiral elongation number along the cathode sheet. It was found that in order to form a representative analytical sample under cathode copper production of the Polar Division of MMC «Norilsk Nickel», the testing of cathodes should be performed using methods that include all areas of the cathode sheet, for example, cutting of a vertical strip from each cathode which has got in a representative sample, including edges and hanging ears. To determine the dependence of the spiral elongation number on the surface quality of copper cathodes, developed a special technique, based on the detection of the most frequently encountered defects in the surface of the cathode sheet, which assigned a certain numerical value in accordance with the ranking results. The proposed scoring system for the quality of cathodes in appearance allowed us to establish for the first time that stabilization of the spiral elongation number at a level of at least 400 mm is possible if the defectiveness of the cathode surface does not exceed 17 points per one electrolysis bath. The method has found practical application for preliminary quantitative estimation of the most widespread superficial defects of copper cathodes in the conditions of current production.

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