Chemo-Mechanical Grinding for K9 Optical Glass

2014 ◽  
Vol 1002 ◽  
pp. 57-60
Author(s):  
Heng Zhen Dai ◽  
Zhen Hua Jiao ◽  
Bin Wang ◽  
Zhu Ji Jin
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
High Surface ◽  
National Defense ◽  
Mechanical Grinding ◽  
Subsurface Cracks ◽  
Glass Specimen ◽  
Check Experiment

K9 optical glass was widely used in national defense and civilian fields. In this paper, chemo-mechanical grinding (CMG) was applied to process the K9 optical glass. Selecting CeO2, MgO and Fe2O3as CMG abrasives, the corresponding CMG tools were purposely developed for the check experiment. High surface and subsurface qualities on the K9 optical glass specimen were obtained as the polished results by the CeO2-CMG tools. Surface roughness and material removal rate were used to evaluate the grinding performance. The low-abrasive ratio of CeO2-CMG tool was proved as the optimal one, by which the surface roughness Ra reached 0.586nm, and the surface morphology appeared smooth and flat. The angle polishing was applied to detect the subsurface quality and the subsurface cracks were not observed.

Chemical Mechanical Grinding Wheel for K9 Optical Glass

2013 ◽  
Vol 712-715 ◽  
pp. 579-583
Author(s):  
Bin Wang ◽  
Heng Zhen Dai ◽  
Zhu Ji Jin
Keyword(s):  
Surface Roughness ◽  
Solid State ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
Processing Parameters ◽  
Wheel Speed ◽  
Grinding Wheel ◽  
Mechanical Grinding ◽  
Dry Grinding

Chemical mechanical grinding (CMG) was applied in machining K9 optical glass. Eight types of CMG wheels were developed and their dry grinding performances were analyzed. The specific CMG wheel which contained 28%vol.abrasive,20%vol.porous and certain additives obtained satisfied surface quality and material removal rate, as result that the solid state reaction and mechanical elimination reached equilibrium. The CMG process parameters, including pressure, workpiece speed and wheel speed, were optimized by using orthogonal experimental method. The surface roughness can reach 0.461nm in Ra on the basis of optimized processing parameters.

scholarly journals Effect of the Lapping Platen Groove Density on the Characteristics of Microabrasive-Based Lapping

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 775
Author(s):  
Taekyung Lee ◽  
Haedo Jeong ◽  
Sangjik Lee ◽  
Doyeon Kim ◽  
Hyoungjae Kim
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Material Removal ◽  
Removal Rate ◽  
High Surface ◽  
Abrasive Particle ◽  
Process Conditions ◽  
Abrasive Particles ◽  
Oil Film ◽  
Process Characteristics

Microabrasive-based lapping is widely used in the manufacturing of single-crystal substrates such as sapphire, SiC, and GaN. Although many studies have been conducted to improve the lapping process characteristics, most of them focused on process conditions or consumables. In this study, the effect of the lapping platen groove density on the lapping characteristics was studied using a sapphire substrate. Groove density was defined as the ratio of groove width to groove pitch, and the displacement of the lapping head was measured to calculate the oil film thickness. It was confirmed that, for groove densities below 0.30, hydroplaning occurs when the oil film thickness increases. When the oil film thickness is larger than the abrasive particle size, the material removal rate is low because the abrasive does not participate in the lapping process. When the oil film was developed, the experimental results showed a high surface roughness and poor flatness of the substrate, as only large abrasive particles participated in the lapping process. Therefore, to improve the lapping characteristics, it is important to reduce the groove density by reducing the groove pitch, which prevents the development of the oil film.

Ultra Smooth Planarization Polishing Technique Based on the Cluster Magnetorheological Effect

2010 ◽  
Vol 135 ◽  
pp. 18-23 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Jie Wen Yan ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Surface Roughness ◽  
Carbonyl Iron ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
Polished Surface ◽  
Mr Fluid ◽  
Magnetorheological Effect ◽  
The Difference ◽  
Mr Effect

A new planarization polishing method based on the cluster magnetorheological (MR) effect is presented to polish optical glass in this paper. Some process experiments were conducted to reveal the influence of the content of carbonyl iron and the abrasive materials in the MR fluid on the machining effect, and the machining characteristic of polished surface was studied. The results indicate that the surface roughness of the polished workpiece can be reduced rapidly when the strong magnetic field is applied, and ultra smooth surface with Ra 1.4 nm can be achieved while the CeO2 abrasives are used in the MR fluid. The content of carbonyl iron obviously influences the machining effect of this planarization polishing method based on cluster MR-effect. With the increase of the content of carbonyl iron in the MR fluid, the material removal rate improves and the surface roughness reduces rapidly. However, the difference of abrasive material results in various machining effects. As for the K9 optical glass, the CeO2 abrasive is better polishing abrasive than the SiC abrasive in the planarization polishing technique based on the cluster MR-effect.

Investigation into Chemo-Mechanical Fixed Abrasive Polishing of Fused Silica with the Assistance of Ultrasonic Vibration

2012 ◽  
Vol 523-524 ◽  
pp. 155-160 ◽  
Author(s):  
Ya Guo Li ◽  
Yong Bo Wu ◽  
Li Bo Zhou ◽  
Hui Ru Guo ◽  
Jian Guo Cao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
Material Removal Rate ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
Fused Silica ◽  
Processing Efficiency ◽  
Machined Surface ◽  
Fixed Abrasive

Ultrasonic vibration assisted processing is well known for the improvement in machined surface quality and processing efficiency due to the reduced forces and tribology-generated heating when grinding hard-brittle materials. We transplanted this philosophy to chemo-mechanical fixed abrasive polishing of optical glass, namely fused silica, in an attempt to improve surface roughness and/or material removal rate. Experiments were conducted to elucidate the fundamental characteristics of chemo-mechanical fixed abrasive polishing of fused silica in the presence and absence of ultrasonic vibration on a setup with an in-house built gadget. The experimental results show that ultrasonic vibration assisted chemo-mechanical fixed abrasive polishing can yield increased material removal rate while maintaining the surface roughness of manufactured optics compared to conventional fixed abrasive polishing without ultrasonic vibration. The mechanism of material removal in fixed abrasive polishing was also delved. We found that the glass material is removed through the synergic effects of chemical and mechanical actions between abrasives and glass and the resultant grinding swarf contains ample Si element as well as Ce element, standing in stark contrast to the polisher that contains abundant Ce element and minor Si element.

Influence of Abrasive on Planarization Polishing with the Tiny-Grinding Wheel Cluster Based on the Magnetorheological Effect

2009 ◽  
Vol 76-78 ◽  
pp. 229-234 ◽  
Author(s):  
Qiu Sheng Yan ◽  
Yong Yang ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Material Removal Rate ◽  
Material Removal ◽  
Magnetic Particles ◽  
Optical Glass ◽  
Removal Rate ◽  
Grinding Wheel ◽  
Material Particle ◽  
Material Removal Model

Experiments were conducted to polish optical glass with the magnetorheological (MR) effect-based tiny-grinding wheel cluster, and the influences of abrasive material, particle size and content on the material removal rate and surface roughness are investigated. The experimental results indicate that: the higher the hardness of abrasives, the higher the material removal rate, but the abrasives with lower hardness can obtain lower surface roughness. The better polishing quality of the workpiece can be obtained when the particle size of abrasives is similar to the particle size of magnetic particles. Moreover, the content of abrasives has an optimum value, and the material removal rate and the surface quality can not be improved further when the content of abrasives exceeds the optimum value. On the basis of above, the material removal model of the new planarization polishing technique is presented.

Study on Machining Process of Lapping for BK7 Glass

2011 ◽  
Vol 487 ◽  
pp. 257-262 ◽  
Author(s):  
Cheng Yong Wang ◽  
Wu Sheng Luo ◽  
C.H. He ◽  
Yue Xian Song
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
Machining Process ◽  
Empirical Formulas ◽  
Machining Time ◽  
Rotating Speed ◽  
Bk7 Glass ◽  
Optimization Parameters

BK7 optical glass is used as the object of study in this paper. The different parameters such as lapping time, load, slurry flow, slurry concentration, abrasive grain sizes, rotating speed effect on surface roughness and material removal volume are studied. Using the way of orthogonal experiments for seeking optimization parameters to gain the smoothness surface and consume the minimum machining time. The empirical formulas of surface roughness and material removal rate are found by orthogonal test.

Research on the Chemical-Mechanical Grinding (CMG) Tools for Al2O3Ceramic

2011 ◽  
Vol 325 ◽  
pp. 270-275
Author(s):  
Heng Zhen Dai ◽  
Zhu Ji Jin ◽  
Shang Gao ◽  
Z.C. Tao
Keyword(s):  
Surface Roughness ◽  
Material Removal ◽  
Removal Rate ◽  
Physicochemical Characteristics ◽  
Grinding Wheel ◽  
Chemical Compositions ◽  
Mechanical Grinding ◽  
Grinding Performance ◽  
Grinding Tool ◽  
Better Than

Aiming at the severe surface/subsurface damage of Al2O3ceramic ground by diamond grinding wheel, the chemical-mechanical grinding (CMG) tools were studied in this paper. According to the principle of CMG, three types of CMG tools with different abrasives were developed. The chemical compositions of the grinding tools were selected and optimized considering the physicochemical characteristics of Al2O3ceramic. By comparing the surface roughness and material removal rate (MRR) of Al2O3ceramic respectively ground with SiO2 , Fe2O3 and MgO grinding tools, the grinding performance of those grinding tools were evaluated. The experiment results showed that the grinding performance of SiO2 grinding tool was the best. The surface roughness and MRR versus SiO2 grinding tool were all better than other grinding tools, and can reach 28 nm and 15 μm/h respectively. The grinding performance of Fe2O3 grinding tool was the worst.

Influence of Magnetic Field Strength on Polishing Effect of the Tiny-Grinding Wheel Cluster Based on the Magnetorheological Effect

2010 ◽  
Vol 443 ◽  
pp. 406-410 ◽  
Author(s):  
Jie Wen Yan ◽  
Qiu Sheng Yan ◽  
Jia Bin Lu ◽  
Wei Qiang Gao
Keyword(s):  
Magnetic Field ◽  
Surface Roughness ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Material Removal Rate ◽  
Carbonyl Iron ◽  
Material Removal ◽  
Optical Glass ◽  
Removal Rate ◽  
Grinding Wheel

A new tiny-grinding wheel cluster polishing method based on the Magnetorheological (MR) effect is presented to polish optical glass in this paper and some process experiments were conducted to reveal the influence of magnetic field strength, the content of carbonyl iron in the MR fluid and the speed of polishing disc on the material removal rate and the surface roughness of the glass workpiece. The results indicate that when the external magnetic field is applied, the material removal rate of the workpiece improves rapidly but the surface roughness increases slightly. When the Magnetic field strength is 100 Gs and the content of carbonyl iron is 3.5%, the material removal rate improves by a factor of 16.8% compared with that of the conventional polishing methods with dissociative abrasive particles, while the surface roughness of the workpiece increases unobviously.

Effects of Process Parameters on Surface Roughness and MRR in the hard turning of EN 36 steel

2018 ◽  
pp. 102-110
Author(s):  
Amritpal Singh ◽  
Rakesh Kumar
Keyword(s):  
Surface Roughness ◽  
Material Removal Rate ◽  
Material Removal ◽  
Hard Turning ◽  
Control Parameter ◽  
Removal Rate ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Dry Cutting

In the present study, Experimental investigation of the effects of various cutting parameters on the response parameters in the hard turning of EN36 steel under the dry cutting condition is done. The input control parameters selected for the present work was the cutting speed, feed and depth of cut. The objective of the present work is to minimize the surface roughness to obtain better surface finish and maximization of material removal rate for better productivity. The design of experiments was done with the help of Taguchi L9 orthogonal array. Analysis of variance (ANOVA) was used to find out the significance of the input parameters on the response parameters. Percentage contribution for each control parameter was calculated using ANOVA with 95 % confidence value. From results, it was observed that feed is the most significant factor for surface roughness and the depth of cut is the most significant control parameter for Material removal rate.

Effect of SiC-Cu Electrode on Material Removal Rate, Tool Wear and Surface Roughness in EDM Process

2020 ◽  
Vol 38 (9A) ◽  
pp. 1406-1413
Author(s):  
Yousif Q. Laibia ◽  
Saad K. Shather
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Material Removal Rate ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
304 Stainless Steel ◽  
Tool Electrode ◽  
Pulse Time ◽  
Edm Process

Electrical discharge machining (EDM) is one of the most common non-traditional processes for the manufacture of high precision parts and complex shapes. The EDM process depends on the heat energy between the work material and the tool electrode. This study focused on the material removal rate (MRR), the surface roughness, and tool wear in a 304 stainless steel EDM. The composite electrode consisted of copper (Cu) and silicon carbide (SiC). The current effects imposed on the working material, as well as the pulses that change over time during the experiment. When the current used is (8, 5, 3, 2, 1.5) A, the pulse time used is (12, 25) μs and the size of the space used is (1) mm. Optimum surface roughness under a current of 1.5 A and the pulse time of 25 μs with a maximum MRR of 8 A and the pulse duration of 25 μs.

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