scholarly journals ELID Mirror Surface Grinding for Concave Molds by Conductive Elastic Wheel Containing Carbon Black

2022 ◽  
Vol 16 (1) ◽  
pp. 21-31
Author(s):  
Atsushi Ezura ◽  
Katsufumi Inazawa ◽  
Kazuhiro Omori ◽  
Yoshihiro Uehara ◽  
Nobuhide Itoh ◽  
...  
Keyword(s):  
Carbon Black ◽  
Removal Rate ◽  
Surface Finishing ◽  
Grinding Wheel ◽  
Butadiene Rubber ◽  
Mirror Surface ◽  
Grinding Wheels ◽  
High Quality ◽  
Shape Accuracy ◽  
Elid Grinding

Elastic grinding wheels have previously been adopted for the development of the mirror surface finishing method for concave spheres. In this study, new conductive elastic grinding wheels, to which electrolytic in-process dressing (ELID) can be applied, are developed; the aim of the study is to address the challenge of maintaining a constant removal rate for rubber bond wheels. When ELID grinding is performed using a non-diene (isobutane isoprene rubber, IIR)-based wheel, a larger removal amount is achieved, and a higher-quality surface is also achieved compared to a diene (acrylonitrile-butadiene rubber, NBR)-based wheel. In addition, to investigate the effect of grinding wheel bond hardness on the removal amount and ground shape accuracy, grinding wheels with various levels of hardness are prepared by controlling the amount of carbon black contained in them, and grinding experiments are conducted. Thus, a larger removal amount is achieved using a harder grinding wheel, but the roughness of the ground surfaces deteriorates. Therefore, in practice, it is necessary to select an appropriate grinding wheel that can achieve both productivity and surface quality. Finally, to obtain a high-quality mirror finish on a concave spherical surface, ELID grinding is performed on the workpieces as is done for spherical lens molds. Thus, high-quality mirror surfaces with roughness Ra < 10 nm were generated. When the work pieces are ground using a grinding wheel of the same radius, excessive removal occurs at the edge of the concave spherical profile, decreasing the form accuracy. Numerical simulation demonstrates that chamfering of the grinding wheel is effective for improving the shape accuracy. The results of this study are expected to contribute to automation and cost reduction in the mirror-finishing process for concave molds.

scholarly journals Effects of O2 Fine Bubbles on ELID Grinding Using Conductive Rubber Bond Grinding Wheel

2019 ◽  
Vol 13 (5) ◽  
pp. 657-664
Author(s):  
Katsufumi Inazawa ◽  
Hitoshi Ohmori ◽  
Nobuhide Itoh ◽  
◽  
Keyword(s):  
High Performance ◽  
Pure Titanium ◽  
Surface Finishing ◽  
Grinding Wheel ◽  
Mirror Surface ◽  
Workpiece Material ◽  
Elid Grinding ◽  
Conductive Rubber ◽  
Grinding Fluid ◽  
Grinding System

This study proposes a new grinding system using grinding fluid containing oxygenic fine bubbles (O2FBs) to realize high-performance electrolytic in-process dressing (ELID) using a conductive rubber bond grinding wheel. It was found that grinding fluid containing O2FBs dramatically increases the dissolved oxygen in the grinding fluid. In addition, the O2FBs in the fluid are drawn to the conductive rubber bond grinding wheel, which is the positive pole, during ELID. These effects are thought to enhance the dressing performance of the conductive rubber bond grinding wheel. Grinding of pure titanium using the proposed grinding system was found to realize mirror surface finishing while increasing the amount of removed workpiece material, compared to when ELID was not applied and to when ELID grinding was conducted using a normal grinding fluid. Effects of ELID grinding on surface modification were also observed, confirming that the proposed grinding system is able to form a thick oxidized film on pure titanium.

Factors Influencing the Performance of Grinding Wheels

1959 ◽  
Vol 81 (3) ◽  
pp. 187-199 ◽  
Author(s):  
E. J. Krabacher
Keyword(s):  
Metal Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Metal Removal Rate ◽  
Grinding Wheels ◽  
Wheel Wear ◽  
Grinding Wheel Wear ◽  
Grinding Ratio ◽  
Material Hardness ◽  
Chip Load

Optimum utilization of grinding wheels can best be achieved if the nature of their performance and wear characteristics, and the factors that affect these characteristics, are understood and applied. As reported in this paper, a comprehensive, continuing, grinding-research program has contributed to such an understanding. A study of the nature of grinding-wheel wear indicates that the grinding-wheel wear curve is similar to those of other cutting tools. It demonstrates further that the type of grinding operation significantly affects the nature of wheel wear. A unique technique has been developed for very accurately measuring grinding-wheel wear. This measured wear may be translated into terms of “grinding ratio,” which is the generally accepted parameter for measuring wheel wear. It is the ratio of the volume of metal removed per unit volume of wheel worn away. Extensive studies have been carried out to determine the effect of mechanical variables on grinding ratio, power required in metal removal, and on surface finish. Experimental findings indicate that grinding ratio decreases with increased metal-removal rate and increases with workpiece diameter, decreased chip load, and increased concentration of grinding fluid. Power is found to increase with both the metal-removal rate and the amount of metal removed. It increases slightly with workpiece diameter and is affected little by work-material hardness. Surface finish is found to improve with decreased metal-removal rate and decreased chip load. It also is affected little by work diameter or work-material hardness. Fundamental research in the mechanics of wheel wear is supplying much additional information in the study of grinding-wheel wear. The measurement of grinding forces employing a cylindrical grinding dynamometer provides the opportunity for relating the wear of grinding wheels to the basic mechanics of the process through such fundamental quantities as grinding forces, specific energy, and grinding friction. Two additional experimental techniques for the study of chip formation in grinding have also proved to be most useful research tools. A “quick-stop” apparatus is used to freeze the grinding action by accelerating a tiny workpiece almost instantaneously to grinding-wheel speed. Another technique permits the comparison of the shape of the grinding grit and that of the contour of its path through the workpiece by a unique replicating method.

Development on Micro Precision Truing Method of ELID-Grinding Wheel (2nd Report: Application to Edge Sharpening of Large Wheel)

2005 ◽  
Vol 291-292 ◽  
pp. 213-220 ◽  
Author(s):  
Shao Hui Yin ◽  
Wei Min Lin ◽  
Yoshihiro Uehara ◽  
Shinya MORITA ◽  
Hitoshi Ohmori ◽  
...  
Keyword(s):  
Surface Quality ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Elid Grinding ◽  
Diamond Grinding ◽  
Grinding Performance ◽  
Profile Accuracy ◽  
Large Wheel ◽  
Edge Sharpening

In V-groove ELID grinding process, to achieve optimal grinding performance and satisfactory surface quality and profile accuracy, metal bonded diamond grinding wheels need to be carefully sharpened. In this paper, we applied the proposed new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing to sharpen the edge of large grinding wheels. The minimum wheel tip radiuses of 6.3 and 8.5µm were achieved for the #4000 and #20000 grinding wheels. The truing mechanisms and sharpening performance are also discussed.

The Influence of Surface Dipping and Bulk Filling Agents on Properties of High-Speed Grinding Wheels: Materialographic-Based Numerical Modelling

2020 ◽  
Vol 405 ◽  
pp. 43-47
Author(s):  
Ladislav Čelko ◽  
Petr Skalka ◽  
Karel Slámečka ◽  
David Jech ◽  
Lenka Klakurková ◽  
...  
Keyword(s):  
High Speed ◽  
Metallic Surface ◽  
Surface Finishing ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Microscope Images ◽  
Safety And Reliability ◽  
High Speed Grinding

In order to increase the peripheral speed of grinding wheels of size of Ø 500 × 18 × Ø 200 mm for precise hard metallic surface finishing from conventional 80 m.s-1 up to 138 m.s-1 while still ensuring their safety and reliability, the critical locations in the grinding wheel were evaluated using the finite element analysis. The microstructure of grinding wheel was revealed using the materialographic techniques and the scanning electron microscope images were recorded in the back-scattered electrons mode. The image analysis was used on recorded micrographs for separation of individual material components, i.e. an abrasive, a binder, and pores, and to extract their geometries and spatial relationships. Subsequently, the influence of different filling agents (Young's modulus of 5, 10, 20, and 40 GPa) was studied, considering both surface dipping and bulk filling treatments.

Investigation on Influences by Adapting Additives to Electrolytic In-Process Dressing (ELID) Grinding

2010 ◽  
Vol 447-448 ◽  
pp. 169-173
Author(s):  
Ning Lou ◽  
Ioan D. Marinescu ◽  
Michael C. Weismiller
Keyword(s):  
Manufacturing Industry ◽  
Grinding Process ◽  
Mirror Surface ◽  
Chemical Additives ◽  
Efficient Technology ◽  
Metallic Oxide ◽  
High Quality ◽  
Elid Grinding ◽  
Before And After ◽  
Hard And Brittle Materials

As demand for high-quality machined tools considerably grows, ELID, a new and efficient technology, has been successfully brought into the precise manufacturing industry of hard and brittle materials with mirror surface finish. Hence, besides conventional functions like lubrication, fluid solutions in this grinding process are required to serve more functions, especially as electrolyte. Writers of this paper mainly work on the methodology to optimize this kind of fluid by adding various related chemical additives. By varying the pH, the accretion of additives is controlled and consequential effects are studied which is the metallic oxide layer variation before and after each test. Corresponding experiments have been carried out with procedures and results analysis included in the paper.

Development on Micro Precision Truing Method of ELID-Grinding Wheel (1st Report: Principle & Fundamental Experiments)

2005 ◽  
Vol 291-292 ◽  
pp. 207-212 ◽  
Author(s):  
Hitoshi Ohmori ◽  
Shao Hui Yin ◽  
Wei Min Lin ◽  
Yoshihiro Uehara ◽  
Shinya MORITA ◽  
...  
Keyword(s):  
High Precision ◽  
High Efficiency ◽  
High Hardness ◽  
Experimental Results ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Elid Grinding ◽  
High Toughness ◽  
Diamond Grinding

Metal bonded diamond grinding wheels are widely used in the grinding process, especial in ELID grinding. However, truing is difficult owing to the high toughness of metal bond materials and high hardness of diamond abrasives. To realize high precision and high-efficiency truing, we propose a new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing in this paper. The process principle and fundamental experimental results are introduced, and the truing performance is discussed. Research results show that the proposed new method is effective for truing metal bonded diamond grinding wheels.

Study on Grinding Mechanism of BCB Grinding Wheel

2012 ◽  
Vol 472-475 ◽  
pp. 2914-2917 ◽  
Author(s):  
Wei Li ◽  
Yang Hong ◽  
Liang Sheng Jin
Keyword(s):  
Surface Roughness ◽  
Removal Rate ◽  
Resin Composite ◽  
Grinding Wheel ◽  
Machining Parameters ◽  
Bamboo Charcoal ◽  
Workpiece Surface ◽  
Elid Grinding ◽  
Grinding Mechanism ◽  
Grinding Technique

BCB(Bamboo Charcoal Bonded) grinding wheel is a new kind of grinding wheel developed by bamboo charcoal-phenolic resin composite for ELID(Electrolysis In-process Dressing) grinding technique. To study the affection of the ground workpiece surface roughness and removal rate with this new kind of grinding technique, the stainless steel SUS304 was ground using BCB grinding wheel in different machining parameters with ELID grinding condition, and the machining characteristics of BCB grinding wheel has been researched. The experimental results indicated that the ground workpiece surface roughness can be reached to Ra 0.010μm, and the efficient and precision machining with BCB grinding wheel by ELID grinding technique has been achieved for hard-to-cut materials. Finally, by studying of the grinding wheel surface condition and wear, the BCB grinding wheel grinding mechanism has been preliminary discussed.

Development in the Dressing of Super Abrasive Grinding Wheels

2009 ◽  
Vol 404 ◽  
pp. 1-10 ◽  
Author(s):  
Berend Denkena ◽  
Luis de Leon ◽  
B. Wang ◽  
Dennis Hahmann
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Fine Grained ◽  
Grinding Processes ◽  
Shifting Strategy ◽  
Contact Discharge

Harder workpiece materials and increased efficiency requirements for grinding processes make the use of super abrasive grinding wheels indispensable. This paper presents newly developed processes for the dressing of super abrasive grinding wheels. The different bond systems of grinding wheels require distinct dressing process. In this paper, dressing processes for metal and vitrified bonded grinding wheels are investigated. It introduces the method of electro contact discharge dressing for the conditioning of metal-bonded, fine-grained multilayer grinding wheels. A description of the essential correlation between dressing parameters and the material removal rate of the bond material is presented. The considered parameters are the dressing voltage, the limitation of the dressing current and the feed as well as the infeed of the electrode. For the grinding of functional microgroove structures, multiroof profiles with microscopic tip geometries are dressed onto the grinding wheel. For this, a profile roller in combination with a special shifting strategy is applied on finegrained vitrified bonded grinding wheels.

Fabrication of High-quality Surfaces on Precise Lens Mold Materials by a new ELID Grinding Wheel

2006 ◽  
pp. 315-318 ◽  
Author(s):  
Tomoyuki Saito ◽  
Kazutoshi Katahira ◽  
Hitoshi Ohmori ◽  
Jun Komotori ◽  
Masayoshi Mizutani ◽  
...  
Keyword(s):  
Grinding Wheel ◽  
High Quality ◽  
Elid Grinding

Manufacturing Technology of α-Fe Bonded Grinding Wheel Free Abrasive

2018 ◽  
Vol 780 ◽  
pp. 111-115 ◽  
Author(s):  
Ji Cai Kuai ◽  
Dmitrii V. Ardashev ◽  
Jia Qi Zhang ◽  
Hua Li Zhang
Keyword(s):  
Oxide Film ◽  
High Surface ◽  
Grinding Wheel ◽  
Mirror Surface ◽  
Precision Grinding ◽  
Abrasive Particles ◽  
Elid Grinding ◽  
Abrasive Grain ◽  
Ultra Precision ◽  
Free Abrasive

ELID ultra-precision grinding mirror surface can achieve nanometer precision. However, after the grinding wheel passivates the abrasive particles in electrolysis, it is easy to scratch the ultra-precision ELID grinding surface into the grinding process. In order to solve this problem, a non-abrasive grain α-Fe bonded grinding wheel is propose, which contains no abrasive particles. After electrolysis, oxide film is formed on the surface of the wheel. In ultra-precision ELID grinding, there is no abrasive particles involved, only the polishing effect of oxide film. There is no need to worry about the scratching of exfoliated abrasive particles that have been machined on ultra-precision ELID surfaces. Thus achieving extremely high surface accuracy.

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