Polishing Characteristics of ELID-Ground Surface of Nano Precision Optical Elements

This paper describes an ultra precision polishing method of aspherical mirrors, and the fundamental research on polishing characteristics. The aspherical mirrors with a diameter of about 30mm made by fused silica glass and CVD-SiC were ELID (electrolytic in-process dressing)-ground to high form accuracy with #4000 cast iron bonded diamond wheel, and then polished with a small polishing tool. As the result, final surface roughness of 1.4nmRa and form accuracy of 1.2 μm was obtained.

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An Experimental Investigation of Optimal Grinding Condition for Aspheric Surface Lens Using Full Factorial Design

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.329.27 ◽

2007 ◽

Vol 329 ◽

pp. 27-32 ◽

Cited By ~ 1

Author(s):

Seung Yub Baek ◽

Jung Hyung Lee ◽

Eun Sang Lee ◽

H.D. Lee

Keyword(s):

Surface Roughness ◽

Ground Surface ◽

Diamond Wheel ◽

Aspheric Surface ◽

Precision Grinding ◽

Spherical Lens ◽

Ultra Precision ◽

Ground Surface Roughness ◽

Grinding System ◽

Micro Lens

To enhance the precision and productivity of ultra precision aspheric surface micro lens, the development of ultra-precision grinding system and process for the aspheric surface micro lens are described. In this paper, an ultra-precision grinding system for manufacturing the aspheric surface micro lens was developed by considering the factors affecting the grinding surface roughness and profile accuracy. This paper deals with the mirror grinding of an aspheric surface micro lens by resin bonded diamond wheel and with the spherical lens of BK7. The optimization of grinding conditions with respect to ground surface roughness and profiles accuracy is investigated by design of experiments.

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On-Machine Precision Form Truing and In-Situ Measurement of Resin-Bonded Spherical Diamond Wheel

Applied Sciences ◽

10.3390/app10041483 ◽

2020 ◽

Vol 10 (4) ◽

pp. 1483 ◽

Cited By ~ 2

Author(s):

Jinhu Wang ◽

Qingliang Zhao ◽

Chunyu Zhang ◽

Bing Guo ◽

Julong Yuan

Keyword(s):

Surface Profile ◽

Ground Surface ◽

Diamond Wheel ◽

In Situ Measurement ◽

Coarse Grained ◽

Alignment Error ◽

Machine Precision ◽

Form Accuracy ◽

Measurement Results

The resin-bonded spherical diamond wheel is widely used in arc envelope grinding, where the demands for form accuracy are high and the form truing process is challenging. In this paper, on-machine precision form truing of the resin-bonded spherical diamond wheel is accomplished by using a coarse-grained diamond roller, and in-situ measurement of the form-truing error is conducted through a laser scan micrometer. Firstly, a novel biarc curve-fitting method is proposed based on the in-situ measurement results to calculate the alignment error between the diamond roller and the spherical diamond wheel. Then, on-machine precision form truing of a D46 resin-bonded spherical diamond wheel is completed after alignment error compensation. The in-situ measurement results show that the low-frequency form-truing error is approximately 5 μm. In addition, the actual form-trued diamond wheel has been employed in grinding a test specimen, and the resulting form accuracy is approximately 1.6 μm without any compensation. The ground surface profile shared similar characteristics with the roller-trued diamond wheel profile, confirming that the diamond roller truing and in-situ measurements methods are accurate and feasible.

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Optimization of Nano-Topography Distribution by Compensation Grinding

International Journal of Automation Technology ◽

10.20965/ijat.2022.p0032 ◽

2022 ◽

Vol 16 (1) ◽

pp. 32-37

Author(s):

Nobuhito Yoshihara ◽

◽

Masahiro Mizuno

Keyword(s):

Spatial Frequency ◽

Ground Surface ◽

View Point ◽

Form Error ◽

Form Accuracy ◽

Optical Surfaces ◽

High Form ◽

Compensation Methods ◽

Measurement Results ◽

Grinding Conditions

Optical surfaces are required to have high form accuracy and smoothness. The form accuracy must be below 50 nm. Form accuracy is currently on the order of several tens of nanometers or less; however, further improvement is required. To improve form accuracy, compensation grinding is performed based on form measurement results. However, when the form error is small, a small periodical waviness occurs on the ground surface, which is known as nano-topography. This waviness cannot be compensated for using conventional compensation methods because the nano-topography distributions are not reproducible. A previous study showed that grinding conditions affect the spatial frequency of nano-topography. Therefore, in this study, optimum grinding conditions are estimated from the view point of nano-topography distributions, and the grinding conditions are compensated to optimize these distributions.

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Precision Grinding of Structured Tungsten Carbide Mold

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.497.15 ◽

2012 ◽

Vol 497 ◽

pp. 15-19 ◽

Cited By ~ 2

Author(s):

Hirofumi Suzuki ◽

Tatsuya Furuki ◽

Mutsumi Okada ◽

Yutaka Yamagata ◽

Shinya MORITA

Keyword(s):

Tungsten Carbide ◽

Power Efficiency ◽

Fresnel Lens ◽

Rare Metal ◽

Diamond Wheel ◽

Precision Grinding ◽

Form Accuracy ◽

Molding Method ◽

Grinding Method ◽

Glass Lens

Demands of glass Fresnel lens is increasing in solar panel in order to increase power efficiency. Glass lens is usually molded by glass molding method with tungsten carbide molds. In this study, large Fresnel lens molds made of tungsten carbide are tested to be ground by simultaneous 2-axis (Y, Z) controlled grinding method. The resinoid bonded diamond wheel was trued with a rare metal truer to improve the sharpness of the wheel edge. In the grinding test of the tungsten carbide mold, a form accuracy of less than 0.8 μm P-V and surface roughness of 18 nm Rz were obtained, and it is clarified that the proposed grinding method is useful for the Fresnel grinding.

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Experimental Study of Grinding Characteristics on SiCp/Al Composites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.487.135 ◽

2011 ◽

Vol 487 ◽

pp. 135-139 ◽

Cited By ~ 3

Author(s):

Li Zhou ◽

Shu Tao Huang ◽

Xiao Lin Yu

Keyword(s):

Volume Fraction ◽

Ground Surface ◽

Diamond Wheel ◽

Feed Speed ◽

Grinding Forces ◽

Electron Microscopic ◽

Sic Particles ◽

Scanning Electron Microscopic ◽

Grinding Machine ◽

Sic Particle

This paper deals with the grinding performances of SiCp/Al composites with higher volume fraction and larger SiC particle. The effects of the grinding parameters on the grinding force, removal mechanisms of SiC particles have been investigated. The grinding tests were carried out by using diamond wheel on surface grinding machine. The results indicate that the feed speed of worktable has more significant effect on the grinding forces than that of grinding depth. The scanning electron microscopic images of the machined surfaces indicate that the material removal of SiC particles was primarily due to the failure of the interface between the reinforcement and matrix, and resulting from microcracks along the interface and many fracture or crushed SiC particles on the ground surface.

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Measurement and Compensation of Tool Contour Error Using White Light Interferometry for Ultra-Precision Diamond Turning of Freeform Surfaces

International Journal of Automation Technology ◽

10.20965/ijat.2020.p0654 ◽

2020 ◽

Vol 14 (4) ◽

pp. 654-664 ◽

Cited By ~ 1

Author(s):

Kodai Nagayama ◽

◽

Jiwang Yan

Keyword(s):

White Light ◽

High Efficiency ◽

Diamond Tool ◽

Microlens Array ◽

Diamond Turning ◽

Contour Error ◽

Form Accuracy ◽

Freeform Optics ◽

Ultra Precision ◽

Quick Measurement

In ultra-precision diamond turning of freeform optics, it is necessary to obtain submicron-level form accuracy with high efficiency. In this study, we proposed a new method for the quick measurement and compensation of tool contour errors to improve the form accuracy of the workpiece. In this method, the nanometer-scale contour error of a diamond tool is quickly and precisely measured using a white light interferometer and then compensated for, before machining. Results showed that the contour of a diamond tool was measured with an error less than 0.05 μm peak-to-valley (P-V) and the feasibility of error compensation was verified through cutting experiments to create a paraboloid mirror and a microlens array. The form error decreased to 0.2 μm P-V regardless of the contour error of the diamond tools when cutting the paraboloid mirror, and that of the microlens array was reduced to 0.15 μm P-V during a single machining step.

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Indentation Crack Initiation and Ductile to Brittle Transition Behavior of Fused Silica

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.797.667 ◽

2013 ◽

Vol 797 ◽

pp. 667-672 ◽

Cited By ~ 3

Author(s):

Peng Yao ◽

Wei Wang ◽

Chuan Zhen Huang ◽

Jun Wang ◽

Hong Tao Zhu ◽

...

Keyword(s):

Penetration Depth ◽

High Efficiency ◽

Fused Silica ◽

Load Range ◽

Brittle Transition ◽

Ductile Mode ◽

Indentation Crack ◽

Ultra Precision ◽

Ductile To Brittle Transition ◽

Brittle Mode

To provide a fundamental knowledge for the high efficiency grinding and ultra-precision grinding of fused silica, ductile mode and brittle mode material removal mechanisms were investigated by conducting micro/nanoindentation experiments in the range of 4.9 mN - 1960 mN. Before observing cracks and determining the ductile to brittle transition penetration depth, the samples were etched with hydrofluoric acid to expose cracks. The typical damage morphology of fused silica was discussed by observing the surface and cross-section of indentations, and the depth of SSD was found to be determined by the cone cracks or borderline cracks in the different load range. The ductile to brittle transition penetration depth of fused silica under Vickers indentation was 180 nm.

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Research on the 3-Axis CNC Ultra-Precision Grinding of Aspheric Mould

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.69-70.39 ◽

2009 ◽

Vol 69-70 ◽

pp. 39-43 ◽

Cited By ~ 1

Author(s):

Li Jun Li ◽

Fei Hu Zhang ◽

Shen Dong

Keyword(s):

Influence Factors ◽

Grinding Wheel ◽

Aspheric Surface ◽

Precision Grinding ◽

Form Accuracy ◽

Form Errors ◽

Machining Test ◽

Ultra Precision ◽

Grinding System ◽

Parallel Grinding

Parallel grinding is an effective method of aspheric moulds machining which is usually made of industrial ceramic such as silicon carbide (SiC) or tungsten carbide (WC), but if the spherical grinding wheel is not being with precision truing and dressing, the roughness and form accuracy of the ground aspheric surface should get worse, for this reason, in this paper, the influence factors of thoroughness and form accuracy induced by the wheel truing and dressing are studied firstly, and a new 3-axis CNC Ultra-precision grinding system which is based on the PMAC (Programmable Multi-axes Controller) is developed, through simultaneous motion of the controlled X, Z and B axis, the form errors which is induced by the grinding wheel can be improved theoretically, and the aspheric mould machining test shown that the surface roughness of Ra 0.025μm and the form accuracy of P-V 1.15μm are achieved.

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