scholarly journals Steel mould surface improvement by robot fluid jet polishing and robot pad polishing for polymer optic production

2019 ◽  
Vol 215 ◽  
pp. 05003
Author(s):  
Rui Almeida ◽  
Timon Ebert ◽  
Rainer Börret ◽  
Mario Pohl
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Geometrical Shape ◽  
Polishing Process ◽  
Shape Deviation ◽  
Mould Surface ◽  
Shape Correction ◽  
Steel Mould ◽  
Surface Improvement

In order to improve the quality of injection-moulded polymer optic parts, it is necessary to improve the quality of the respective steel moulds. For this reason, it is not only necessary to improve the surface roughness of the mould, but also its geometrical shape. The material removal obtained from robot pad polishing is too low. This makes a shape correction after the milling step a very prolonged process. The aim of this work is to use a polishing chain to improve the surface quality of steel samples in terms of shape deviation and surface roughness. This correction polishing chain uses the robot fluid jet polishing for the geometrical shape correction and afterwards the robot pad polishing for the improvement of the surface roughness. Due to the high material removal rates of the fluid jet polishing, it is possible to correct the geometrical shape of steel moulds very fast up to a certain deviation. The pad polishing process improves the surface roughness of the steel samples. A correction of the shape deviation of more than 80% with a RMS of approximately 8 nm was obtained.

scholarly journals Investigation of Polishing Characteristics for Aspherical Lenses Manufacturing

Mechanika ◽  
2020 ◽  
Vol 26 (5) ◽  
pp. 457-461
Author(s):  
Nerijus KADZEVIČIUS ◽  
Ieva ŠVAGŽDYTĖ ◽  
Justinas GARGASAS ◽  
Mindaugas JUREVIČIUS ◽  
Artūras KILIKEVIČIUS
Keyword(s):  
Surface Roughness ◽  
Penetration Depth ◽  
Cnc Machine ◽  
Polishing Process ◽  
Shape Deviation ◽  
Technical Parameters ◽  
Long Time ◽  
Aspherical Lenses ◽  
Five Axis

There were used the spherical lenses in industry conventional for long time, but new types of lenses were created during innovation processes. One type of lenses is aspherical. Two main parameters describing quality of aspherical lenses are accuracy of the form shape and surface roughness. These parameters can be obtained after last operation – polishing. Technical parameters that give the biggest influence to form shape and surface roughness were investigated in this experiment and optimal technical parameters for polishing process were established. Melted quartz ,,UVFS” was used in this research, investigations were carried out according by full factorial design. Five axis CNC machine Schneider SCPA100 was used for polishing and profilometer Nanoscan 855 was used for measurements. After analysis of results it was found out that speed of rotation and penetration depth are the most important factors in polishing process. For getting the best shape it’s necessary to use the smallest chosen values of speed of rotation and penetration depth, for getting the best surface roughness polishing parameters changing conversely. The smallest value of surface roughness Rz was 0.06 µm, and shape deviation was 2.6 µm. Optimal polishing parameters for the best quality of aspherical lenses was provided.

Comparison of Processing Features between Semi Bonded Abrasive Lapping and Loose Abrasive Lapping

2009 ◽  
Vol 416 ◽  
pp. 439-442
Author(s):  
Xun Lv ◽  
Ju Long Yuan ◽  
Dong Hui Wen
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Processing Parameters ◽  
Good Surface ◽  
Ultra Precision ◽  
New Processing ◽  
Short Time

Semi bonded abrasive lapping is an effective ultra-precision lapping method. It can obtain good surface quality of workpiece in short time. This paper focused on the differences of processing features by comparing semi bonded abrasive lapping and loose abrasive lapping in several groups processing parameters. The results showed that the surface roughness of workpiece in semi bonded abrasive lapping was far superior to that of loose abrasive lapping in same processing parameters. And the MRR (material removal rate) of semi bonded abrasive lapping was slightly lower than that of loose abrasive lapping. For these features of semi bonded abrasive, a new processing flow would also be proposed in this paper.

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.

Effect of Free Abrasive Particle in Gasbag Polishing Technique

2009 ◽  
Vol 69-70 ◽  
pp. 83-87
Author(s):  
Ming Sheng Jin ◽  
Shi Ming Ji ◽  
Li Zhang ◽  
Xian Zhang ◽  
Ya Qi Shen
Keyword(s):  
Material Removal ◽  
Abrasive Particle ◽  
General Distribution ◽  
Material Removal Mechanism ◽  
Polishing Process ◽  
Mould Surface ◽  
Movement Characteristic ◽  
Distribution State ◽  
Polishing Efficiency ◽  
Free Abrasive

Free abrasive particle plays a crucial role in material removal and quality improvement of curved surface mould. In order to observe and investigate the general distribution state, fractal dimension and movement characteristic of abrasive particle in gasbag polishing process better, an abrasive particle stroboscopic photography system is established and polishing experiment is carried out. The abrasive particle contacts with not only the rubber gasbag enwrapped by polishing cloth full of mesh-like structures, but also the mould surface. Contact analysis of abrasive particle including the discussions of contact state, material removal mechanism and advantage of precession polishing is helpful to hold the optimal polishing process parameters combination and establish ideal abrasive particle field for higher polishing efficiency and more well-proportioned surface quality.

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.

An Approach to the Influence of Flotative Abrasive Balls on Polishing Process

2006 ◽  
Vol 532-533 ◽  
pp. 393-396 ◽  
Author(s):  
Yong Dai ◽  
Qian Fa Deng ◽  
Xun Lv ◽  
Ju Long Yuan ◽  
Xun Jie Yu
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Removal Rate ◽  
Great Influence ◽  
Work Piece ◽  
Polishing Process ◽  
Soft Contact ◽  
Ball Diameter ◽  
Experiment Device

Polishing with Flotative Abrasive Balls(FABs) is a kind of soft contact polishing means， and the conventional polishing plate and pad are not needed in this case. The pressure of polishing is the flotage which is the upward force that a fluid exerts on the FABs, but the movement of work piece is similar to that in conventional polishing, the removal rate and quality of polishing is influenced by FAB and its flotage. An experiment device is built up and two kinds of FAB are designed and produced. Some primary experiments are carried out in order to investigate the influences of the size of FABs on the removal rate and surface roughness in polishing with FABs. It is found from the experiments that the grain size and the layers of FAB may have great influence on the removal rate of polishing; the surface roughness is mainly decided by the ball diameter and the layers of FAB. The results of experiments are discussed and analyzed, it indicates that the efficiency and quality depend on flotage and the number of active grains when the velocity of workpiece is assigned.

Effects of abrasive types on the surface integrity of abrasive-flow-machined surfaces

2016 ◽  
Vol 232 (6) ◽  
pp. 1044-1053 ◽  
Author(s):  
Kursad Gov ◽  
Omer Eyercioglu
Keyword(s):  
Surface Roughness ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
White Layer ◽  
Machining Process ◽  
Wire Electrical Discharge Machining ◽  
Abrasive Flow Machining ◽  
The Media ◽  
Surface Improvement

In this article, the effect of abrasive types on the abrasive flow machining process was investigated. Four groups of abrasive media were prepared with different types of abrasives: SiC, AL2O3, B4C and Garnet. An experimental study was performed on DIN 1.2379 tool steel. The specimens were cut using wire electrical discharge machining and finished with the abrasive flow machining process. The results show that the white layer that formed during wire electrical discharge machining was successfully removed by abrasive flow machining in a few cycles. Although the surface roughness improves with similar trends for all media groups, the results show that the media prepared with B4C and SiC have more surface improvement than the Al2O3 and Garnet ones. The resulting average surface roughness (Ra) values are comparable to the surface quality of those obtained from lapping and super-finishing. The material removal is directly related to the hardness of the abrasive.

Research on Flexible Bonnet Polishing Process Method and Related Technology

2012 ◽  
Vol 490-495 ◽  
pp. 2916-2920
Author(s):  
Shu Jing Sha ◽  
Long Shan Wang ◽  
Yong Jie Shi
Keyword(s):  
Free Surface ◽  
Material Removal ◽  
Dwell Time ◽  
Polishing Process ◽  
Bonnet Polishing ◽  
The Core ◽  
Ultra Precision ◽  
Polishing Tool ◽  
Process Method

Bonnet tool polishing is one kind of methods that can obtain higher surface quality of the ultra precision processing for producing flat, aspheric and other mould free surface, etc. The latest development and research results on bonnet polishing technology at home and abroad were reviewed. The core technologies of bonnet polishing were analyzed, including polishing principles, polishing tool, the rate of material removal, edge control, dwell time, path planning etc. The results show that the bonnet polishing method is an economic, efficient, practical and high precision polishing technology.

Effects of Magnetic Fluid on Machining Characteristics in Magnetic Field Assisted Polishing Process

2013 ◽  
Vol 797 ◽  
pp. 396-400
Author(s):  
Shao Hui Yin ◽  
Zhi Qiang Xu ◽  
Hong Jie Duan ◽  
Feng Jun Chen
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Magnetic Fluid ◽  
Material Removal ◽  
Magnetorheological Fluid ◽  
Magnetic Fluids ◽  
Magnetic Characteristics ◽  
Polishing Process ◽  
Magnetic Cluster ◽  
Machining Characteristics

Magnetic characteristics of three magnetic polishing fluids such as magnetic fluid (MF), magnetorheological fluid (MRF), and magnetic compound fluid (MCF) under magnetic field are experimentally investigated and analyzed. Their magnetic cluster structures under action of magnet field are observed, and their magnetic cluster models are established. Magnetic flied assisted polishing experiments for tungsten carbide are developed used these three kinds of magnetic fluids, material removal and surface roughness are respectively measured. At last, the machining characteristic of three magnetic fluids are contrasted and discussed according to experimental results.

Material Removal Model of Lap Grinding for Sapphire Substrate Based on Roughness Parameters

2017 ◽  
Vol 890 ◽  
pp. 384-387
Author(s):  
Hyun Seop Lee ◽  
Taek Yung Lee
Keyword(s):  
Surface Roughness ◽  
Sapphire Substrate ◽  
Material Removal ◽  
High Hardness ◽  
Mechanical Polishing ◽  
Geometrical Shape ◽  
Machining Processes ◽  
Material Removal Model ◽  
Semiconductor Circuits ◽  
Mechanical Machining

Sapphire is one of difficult-to-machine materials because of its high hardness and brittleness. It can be used for an optical window or cover named as sapphire glass and a substrate for semiconductor circuits. Before preparing the required surface roughness of sapphire substrate, the geometrical shape should be retained through mechanical machining processes. The lapping and diamond mechanical polishing (DMP) are essentially used for achieving the required thickness and surface roughness of sapphire substrate prior to chemical mechanical polishing (CMP). In this study, we introduce a lap grinding process using fixed abrasives to substitute lapping and DMP. The material removal rates (MRRs) were measured under various machining conditions. The semi-empirical model on MRR was introduced based on the information of grinding pallet. This paper may provide a preliminary experimental study on the lap grinding of sapphire substrate.

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