Ultraprecision Ductile Grinding of Optical Glass Using Super Abrasive Diamond Wheel

2007 ◽  
Vol 339 ◽  
pp. 382-388 ◽  
Author(s):  
Qing Liang Zhao ◽  
Ekkard Brinksmeier ◽  
Otmann Riemer ◽  
Kai Rickens
Keyword(s):  
Grain Size ◽  
Optical Glass ◽  
Diamond Wheel ◽  
Force Transducer ◽  
Coarse Grained ◽  
Experimental Result ◽  
Grinding Wheels ◽  
Diamond Grinding ◽  
Ductile Grinding ◽  
Diamond Grain

In this paper, a novel conditioning technique features using copper bonded diamond grinding wheels of 91μm grain size assisted with ELID (electrolytic in-process dressing) as a conditioner to precisely and effectively condition nickel electroplated monolayer coarse-grained diamond grinding wheels of 151μm grain size was firstly developed. Under optimised conditioning parameters, the super abrasive diamond wheel was well conditioned in terms of a minimized run-out error and flattened diamond grain surfaces of constant peripheral envelope, with the conditioning force monitored by a force transducer as well as the modified wheel surface status in-situ monitored by a coaxial optical distance measurement system. Finally the grinding experiment on BK7 was conducted using the well conditioned wheel with the corresponding surface morphology and subsurface damage measured by AFM (atomic force microscope) and SEM (scanning electron microscope) respectively. The experimental result shows that the newly developed conditioning technique is applicable and feasible to ductile grinding optical glass featuring nano scale surface roughness, indicating a prospect of introducing super abrasive diamond wheels into ductile machining of brittle materials.

ELID Assisted Precision Conditioning of Coarse-Grained Diamond Grinding Wheel

2007 ◽  
Vol 364-366 ◽  
pp. 578-583 ◽  
Author(s):  
Qing Liang Zhao ◽  
Ekkard Brinksmeier ◽  
Otmann Riemer ◽  
Kai Rickens
Keyword(s):  
Optical Glass ◽  
Diamond Wheel ◽  
Force Transducer ◽  
Coarse Grained ◽  
Experimental Result ◽  
Grinding Wheel ◽  
Wheel Surface ◽  
Diamond Grinding Wheel ◽  
Diamond Grinding ◽  
Ductile Machining

In order to realize ductile machining of optical glasses using mono-layer nickel electroplated coarse-grained diamond grinding wheel, a novel conditioning technique features using a copper bonded diamond grinding wheels of 15m grain size dressed by ELID (electrolytic inprocess dressing) to condition the 46m grain sized diamond wheel has been developed. During the conditioning process, a force transducer was used to monitor the conditioning force, a coaxial optical distance measurement system was used to in-situ monitor the modified wheel surface status. White-light interferometry (WLI), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the conditioned wheel surface status as well as the ground optical glass surface topography correspondingly. The experimental result indicates that a minimized wheel radial run-out error of less than 2μm as well as the top-flattened diamond grains of constant wheel peripheral envelop profile were generated on a 5-axis ultra-precision machine tool. The grinding experiment proved that the well conditioned 46μm coarse-grained diamond wheel can be used in realizing the ductile grinding of optical glass BK7, which indicates that the newly developed conditioning technique is feasible and applicable to introduce the coarse-grained diamond wheels into precision machining of brittle and hard-to-machine materials.

Fabrication of Diamond Micro Tool Array (DMTA) for Ultra-Precision Machining of Brittle Materials

2007 ◽  
Vol 329 ◽  
pp. 737-742 ◽  
Author(s):  
Qing Liang Zhao ◽  
Da Gang Xie ◽  
Ekkard Brinksmeier ◽  
Otmann Riemer ◽  
Kai Rickens
Keyword(s):  
Grain Size ◽  
Brittle Materials ◽  
Force Transducer ◽  
Coarse Grained ◽  
Experimental Result ◽  
Grinding Wheel ◽  
Diamond Grinding ◽  
Ductile Machining ◽  
Wheel Topography ◽  
Micro Tool

A novel conditioning technique to precisely and effectively condition the nickel electroplated mono-layer coarse-grained diamond grinding wheel of 91m grain size was developed to fabricate a Diamond Micro Tool Array (DMTA) in ductile machining of brittle materials. During the fabricating process, a copper bonded diamond grinding wheels (91m grain size) dressed by ELID (electrolytic in-process dressing) was applied as a conditioner, a force transducer was used to monitor the conditioning force, and a coaxial optical distance measurement system was used to insitu monitor the modified wheel surface status. The experimental result indicates that the newly developed conditioning technique is applicable and feasible to generate required wheel topography of less than 2μm run-out error and grain geometries. The taper cutting test on BK7 proves the fabricated DMTA is capable of realizing ductile machining of brittle materials.

ELID Assisted Grinding of Optical Glass with Fine and Coarse Grained Copper-Resin Bonded Diamond Wheels

2009 ◽  
Vol 76-78 ◽  
pp. 76-81 ◽  
Author(s):  
Qing Liang Zhao ◽  
Jun Yun Chen ◽  
Jun Yao
Keyword(s):  
Smooth Surface ◽  
Optical Glass ◽  
Surface Damage ◽  
Diamond Wheel ◽  
Coarse Grained ◽  
Nanometer Scale ◽  
Grinding Wheels ◽  
Fine Grained ◽  
Good Surface ◽  
High Efficient

In this paper, a copper-resin bonded diamond wheel was applied to machine the optical glass on a precision grinder. The process of truing and pre-dressing with ELID (electrolytic in-process dressing) were first carried out for the grinding wheels, then the ELID assisted grinding experiments were conducted with the special fine and coarse grained diamond wheels. The experimental results show that the fine and coarse grained wheels can all generated the smooth surface with the surface roughness in nanometer scale and the coarse grained diamond wheel correlates to the slightly more surface damage than the fine grained diamond wheel, which also proves that the high efficient grinding of the optical glass with a good surface quality can be realized with the coarse grained copper-resin wheel on a precision grinder and the grinding wheels were all well conditioned with the conditioning method presented in this paper.

Surface and Sub-Surface Integrity of Ultra- Machined BK7 Using Fine and Coarse Grained Diamond Wheels

2007 ◽  
Vol 359-360 ◽  
pp. 234-238 ◽  
Author(s):  
Qing Liang Zhao ◽  
Bo Wang ◽  
Ekkard Brinksmeier ◽  
Otmann Riemer ◽  
Kai Rickens ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
High Surface ◽  
Coarse Grained ◽  
Nanometer Scale ◽  
Grinding Wheels ◽  
Fine Grained ◽  
Optical Glasses ◽  
Diamond Grinding ◽  
Surface Damages

This paper aims to evaluate the surface and sub-surface integrity of optical glasses which were correspondingly machined by coarse and fine-grained diamond grinding wheels on Tetraform ‘C’ and Nanotech 500FG. The experimental results show that coarse-grained diamond grinding wheels are capable of ductile grinding of optical glasses with high surface and sub-surface integrity. The surface roughness values are all in nanometer scale and the sub-surface damages are around several micros in depth, which is comparative to those machined by fine-grained diamond wheels.

Präzisionsschleifen mit groben Diamantkörnern*/Precision grinding with coarse diamond grains - Application characteristics of coarse-grained diamond grinding wheels

2016 ◽  
Vol 106 (06) ◽  
pp. 387-393
Author(s):  
D. Berger ◽  
M. Althoff ◽  
K. Rickens ◽  
C. Heinzel ◽  
E. Prof. Brinksmeier
Keyword(s):  
Coarse Grained ◽  
Depth Of Cut ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Diamond Grinding ◽  
Measuring Surface ◽  
Ductile Mode ◽  
Different Depths ◽  
Application Characteristics ◽  
Grinding Kinematics

Der Fachbeitrag beschreibt die Weiterentwicklung von galvanisch einschichtig belegten grobkörnigen Diamantschleifscheiben – auch Engineered Grinding Wheels genannt. Verschiedene sprödharte Werkstoffe wurden anhand von Quer-Umfangs-Planschleifversuchen mit angestellter Probenoberfläche bearbeitet. Anhand der Oberflächenqualität und der Bauteilrandzone wurde anschließend der Einfluss einer variierten Zustellung sowie der Prozesskinematik auf einen duktilen Schleifprozess untersucht.   This study describes the application of coarse-grained diamond grinding wheels with electroplated abrasive single-layers (engineered grinding wheels) for ductile mode grinding of different brittle materials. Grinding experiments were performed in cross grinding kinematics while the workpiece is tilted in order to achieve different depths of cut over the workpiece’s surface. Influence of kinematics and depth of cut are investigated by measuring surface roughness and subsurface damage.

New Tool Concepts for Ultra-Precision Grinding

2012 ◽  
Vol 516 ◽  
pp. 287-292 ◽  
Author(s):  
Ekkard Brinksmeier ◽  
Yildirim Mutlugünes ◽  
Grigory Antsupov ◽  
Kai Rickens
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Surface Finish ◽  
Cvd Diamond ◽  
Coarse Grained ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Diamond Grinding ◽  
Ultra Precision ◽  
Sharp Edges

This paper presents advanced tools for ultra precision grinding which offer a high wear resistance and can be used to generate high-quality parts with an ultraprecise surface finish. The first approach features defined dressed, coarse-grained, single layered, metal bonded diamond grinding wheels. These grinding wheels are called Engineered Grinding Wheels and have been dressed by an adapted conditioning process which leads to uniform abrasive grain protrusion heights and flattened grains. This paper shows the results from grinding optical glasses with such Engineered Grinding Wheels regarding the specific forces and the surface roughness. The results show that the cutting mechanism turns into ductile removal and optical surfaces are achievable. On the other hand, the specific normal force F´n increases due to increased contact area of the flattened diamond grains. It is shown that the topography of the Engineered Grinding Wheels has a strong beneficial influence on surface roughness. The second new tool for ultra precision grinding is made of a CVD (Chemical Vapour Deposition) poly-crystalline diamond layer with sharp edges of micrometre-sized diamond crystallites as a special type of abrasive. The sharp edges of the crystallites act as cutting edges which can be used for grinding. It is shown that by using CVD-diamond-coated grinding wheels a high material removal rate and a high surface finish with surface roughness in the nanometre range can be achieved. The CVD-diamond layers exhibit higher wear resistance compared to conventional metal and resin bonded diamond wheels. In conclusion, this paper shows that not only conventional fine grained, multi-layered resinoid diamond grinding wheels but also coarse-grained and binderless CVD-coated diamond grinding wheels can be applied to machine brittle and hard materials by ultra precision grinding.

Development of a New Truing Device Based on Electro-Contact Discharge Machining for Metal Bond Grinding Wheels

2016 ◽  
Vol 874 ◽  
pp. 268-271 ◽  
Author(s):  
Masahiro Mizuno ◽  
Akira Karibe ◽  
Nobuhito Yoshihara ◽  
Naohiro Nishikawa ◽  
Toshiro Iyama
Keyword(s):  
Grain Size ◽  
Diamond Wheel ◽  
The Other ◽  
Grinding Wheels ◽  
Metal Bond ◽  
Working Face ◽  
Grinding Conditions ◽  
Dry Conditions ◽  
Contact Discharge ◽  
Shape And Size

Metal bond grinding wheels can retain their shape and size under extreme grinding conditions. On the other hand, it is difficult to true them accurately and efficiently due to the severe wear of truing tools. To solve the problem, this paper proposes a new truing device based on electro-contact discharge machining. The device is designed so that the position of the electrode working face remains unchanged even if the electrode is worn. Some truing experiments were carried out using a prototype truing device for a metal bond diamond wheel of grain size #1000 under dry conditions. As a result, relatively high truing accuracy has been achieved in combination with an additional truing by a GC stone.

A Study on Grinding Brittle Material with Pattern-Dressed Wheel

2016 ◽  
Vol 861 ◽  
pp. 14-19
Author(s):  
Pei Lum Tso ◽  
Weng Hong Lin
Keyword(s):  
Contact Area ◽  
Brittle Materials ◽  
High Hardness ◽  
Diamond Wheel ◽  
Depth Of Cut ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Specific Grinding Energy ◽  
Diamond Grinding ◽  
Selection Parameters

The high hardness of brittle materials always make it hard to machine with traditional grinding wheels. Conventionally a diamond grinding wheels was used to improve the poor processing capability. Usually the specific grinding energy had been used as an indicator of machinability. According to its definition, the specific grinding energy increases with the active contact area of the grinding wheel decreases. In other words, reducing the surface contact area of the grinding wheel can enhance the specific grinding energy effectively. Conditioning grooves on grinding wheels not only enhance the specific grinding energy, but also achieve the effect of reducing the heat dissipated during the grinding processes. With the proper selection parameters, the high cost of diamond grinding wheel may be replaced by less expensive conventional green carbon and aluminum oxide wheel. In this studies, the relationship between the surface topography of grinding wheels and the grinding capability of brittle materials was investigated. The results show that, the traditional grinding wheel dressing properly while the depth of cut less than 20μm with the rhombic pattern and the depth of cut more than 20μm with the groove-like pattern can grind the brittle materials as good as using diamond wheel.

Performance of Diamond and Silicon Carbide Wheels on Grinding of Bioceramic Material Under Minimum Quantity Lubrication Condition

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
P. Suya Prem Anand ◽  
N. Arunachalam ◽  
L. Vijayaraghavan
Keyword(s):  
Silicon Carbide ◽  
Surface Finish ◽  
Minimum Quantity Lubrication ◽  
Diamond Wheel ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Grinding Wheels ◽  
Diamond Grinding Wheel ◽  
Diamond Grinding ◽  
Wheel Loading

Advanced ceramic materials like sintered and presintered zirconia are frequently used in biomedical applications, where minimum quantity lubrication (MQL) assisted grinding is required to achieve a good surface finish instead of conventional flood coolant. However, insufficient cooling and wheel clogging are the major problems that exist in the MQL grinding process, which depends upon the type of work piece material and the grinding wheel being used. The present study is to determine the performance of the grinding wheels on presintered zirconia under MQL conditions in terms of grinding forces, specific energy, surface integrity, and wheel wear. Experiments are conducted with two different types of grinding wheels as silicon carbide (SiC) and diamond grinding wheels under the same condition. The results indicated that the diamond wheel provided a better surface finish and reduced tangential force under MQL condition, compared to the conventional SIC wheel. This was due to the reduction of wheel loading in the diamond grinding wheel. The specific energy of diamond grinding wheel was reduced with higher material removal rate compared to the conventional SiC wheel. The ground surfaces generated by the diamond grinding wheel showed fine grinding marks with better surface finish. The percentage of G-ratio calculated for the diamond wheel was higher than the SiC wheel by 77%. This was due to the sliding of the grains and less wheel loading in the diamond wheel. The cost difference between the corresponding wheels was discussed to improve the productivity of the grinding process.

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