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.

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.

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.

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.

Surface Quality Analysis in Mill-Grinding of SiCp/Al

2011 ◽  
Vol 299-300 ◽  
pp. 1060-1063 ◽  
Author(s):  
Y.X. Yao ◽  
Jin Guang Du ◽  
Jian Guang Li ◽  
H. Zhao
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Surface Defect ◽  
Quality Analysis ◽  
Grinding Wheel ◽  
Grinding Wheels ◽  
Machined Surface ◽  
Diamond Grinding Wheel ◽  
Diamond Grinding ◽  
Machined Surface Roughness

Mill-grinding experiments were carried out on SiCp/Al to investigate effects of mill-grinding parameters and grinding wheel parameters on machined surface roughness in this paper. The machined surface topography was also analyzed. Experimental results show that surface roughness increases with increasing feed rate and the depth of the mill-grinding. The effect of mill-grinding speed on surface roughness is low. The machined surface reveals many defects. The fine grit diamond grinding wheel can reduce the surface roughness and decrease the machined surface defect. Compared to the vitrified bonded diamond and electroplated diamond grinding wheels used in the experiment, the resin-based diamond grinding wheel produces a better surface.

Surface Integrity of AlSiC Composites Ground by Monolayer Brazed Diamond Wheels

2016 ◽  
Vol 1136 ◽  
pp. 526-530
Author(s):  
Feng Lin Zhang ◽  
Peng Liu ◽  
Peng Wang ◽  
Yu Mei Zhou ◽  
Hui Ping Huang ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
Volume Fraction ◽  
Ground Surface ◽  
Mesh Size ◽  
Diamond Wheel ◽  
The Other ◽  
Grinding Wheels ◽  
Sic Particles ◽  
Finer Diamond

Monolayer brazed diamond wheel were used to grind AlSiC composite with different volume fraction of SiC. The effects of diamond mesh size of the grinding wheels and the volume fraction of SiC in AlSiC composite on the surface integrity of ground AlSiC composite were investigated. It is found that the surface roughness of ground AlSiC composite with 20% SiC is increased with the reduction of diamond grit’s size because of the clogging of diamond wheel. With the increasing of the volume fraction of SiC, there are more fractured and cracked SiC particles on the ground surface of AlSiC composite. On the other hand, the finer diamond grits (70/80) induce the finer fractured SiC particles on the ground surface of AlSiC with 50% and 70% SiC.

High Efficiency Precision Surface Grinding of Fused Silica

2011 ◽  
Vol 418-420 ◽  
pp. 1132-1136 ◽  
Author(s):  
Peng Yao ◽  
Ya Dong Gong ◽  
Suo Xian Yuan ◽  
Nobuhito Yoshihara ◽  
Ji Wang Yan ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Integrity ◽  
High Efficiency ◽  
High Surface ◽  
Chip Thickness ◽  
Diamond Wheel ◽  
Fused Silica ◽  
Wheel Wear ◽  
Undeformed Chip Thickness ◽  
Creep Feed

High efficiency and high surface integrity grinding of fused silica lens used in the ultraviolet (UV) laser transmission equipments is highly demanded. It is necessary to decrease the undeformed chip thickness for producing better surface integrity. We conducted creep feed grinding (CFG) and conventional shallow cut grinding (SCG) experiments of fused silica with a resin bond diamond wheel. Experiment results shows that owing to thinner undeformed chip thickness, the normal grinding force, radial wheel wear and P-V value of surface roughness of CFG are smaller than those of SCG at the same MRR. At the same table speed, surface roughness decreased with the increase of MRR in both CFG and SCG as a result of decreased undeformed chip thickness which is attributed to the elasticity of resin bond.

scholarly journals High performance peel grinding of steel shafts using coarse electroplated CBN grinding wheels

2021 ◽  
Author(s):  
B. Denkena ◽  
A. Krödel ◽  
M. Wilckens
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Material Removal ◽  
High Performance ◽  
High Surface ◽  
Work Piece ◽  
Hard Machining ◽  
Grinding Wheels ◽  
Removal Rates ◽  
High Surface Quality

AbstractGrinding is widely known for its low material removal rates and high surface quality. However, recent developments in production processes for cubic boron nitride (CBN) abrasive grains have led to commercially available grain sizes larger than 300 µm. These superabrasive CBN-grains allow higher material removal rates during grinding of hardened steel components. Currently, these components are pre-machined with turning processes before hardening and finishing the work piece by grinding. However, the turning process can be eliminated by grinding with coarse CBN-grains since higher depths of cut are achievable when machining hardened components. This paper explores the limits of grinding wheels using grains with a size of B602 during soft and hard machining in comparison to conventional B252 grains. It is shown that the use of coarser grains leads to lower process forces, higher (tensile) residual stress and higher surface roughness. Residual stress and surface roughness are of less importance as these grains are to be used mainly in roughing operations with ensuing finishing operations for the required surface properties. Over all investigations, especially in hard machining, neither grain nor tool wear was observed for the B602 grains, whereas the B252 tool was severely clogged during the experiments. Additionally, the grinding force ratio indicates that the coarse grain tools have not yet reached their productivity limit as it increases over all investigated feeds. This indicates improving tool performance with lower amounts of rubbing for increasing feed rate during hard grinding and shows the potential for the industrial use of higher feed rates with larger grains.

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.

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