Dressing of Grinding Wheels for Ultra Precision Grinding of Diffractive Structures in Tungsten Carbide Molds

2014 ◽  
Vol 625 ◽  
pp. 161-166 ◽  
Author(s):  
Thomas Bletek ◽  
Fritz Klocke ◽  
Martin Hünten ◽  
Olaf Dambon
Keyword(s):  
Tungsten Carbide ◽  
Grinding Wheel ◽  
Geometric Features ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Form Accuracy ◽  
Fine Grained ◽  
Diffractive Structure ◽  
Ultra Precision ◽  
Diffractive Structures

The manufacturing of molds with diffractive structures requires new approaches in terms of grinding wheel geometry and preparation. To be able to manufacture small geometric features such as widths and depths in the micron range on the mold, ideally sharp edged grinding wheels should be used. This paper will present dressing procedures to create sharp edged grinding wheels by using metal alloy blocks. The results and achieved tip radii of the dressed resin bonded and metal bonded fine grained grinding wheels will be presented. Finally, grinding tests of a tungsten carbide mold with a diffractive structure are conducted and the results of the achieved form accuracy and surface roughness are presented.

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

2009 ◽  
Vol 69-70 ◽  
pp. 39-43 ◽  
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.

Precision Grinding of Structured Tungsten Carbide Mold

2012 ◽  
Vol 497 ◽  
pp. 15-19 ◽  
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.

Development of Vitrified Bond CBN Wheel for Internal Precision Grinding of the Air-Conditioner Compressor Piston Hole

2006 ◽  
Vol 304-305 ◽  
pp. 29-32 ◽  
Author(s):  
Hang Gao ◽  
Y.G. Zheng ◽  
W.G. Liu ◽  
Jian Hui Li
Keyword(s):  
Cost Effective ◽  
Grinding Wheel ◽  
Manufacturing Cost ◽  
Air Conditioner ◽  
Grinding Wheels ◽  
Precision Grinding ◽  
Grinding Performance ◽  
Compressor Piston ◽  
Vitrified Bond ◽  
Cbn Grinding Wheel

Manufacturing of vitrified bond CBN wheels for internal precision grinding of the air-conditioner compressor piston hole is still big challenge to all of the domestic manufacturers. Recently, by choosing pre-melting mixed CBN abrasives and a proper sintering process, a cost-effective method was conceived to produce grinding wheels of comparative quality. The grinding performance of wheels was evaluated with a series of internal precision grinding of compressor piston hole. Experimental results show that the vitrified bond CBN grinding wheel produced by this method has better grinding performance, and can be substitute to the same type of grinding wheels imported. But the manufacturing cost is only 60% of the wheel imported according to estimation.

Precision Cutting of Structured Ceramic Molds with Micro PCD Milling Tool

2011 ◽  
Vol 5 (3) ◽  
pp. 277-282 ◽  
Author(s):  
Hirofumi Suzuki ◽  
◽  
Tatsuya Furuki ◽  
Mutsumi Okada ◽  
Katsuji Fujii ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Tungsten Carbide ◽  
Polycrystalline Diamond ◽  
Micro Milling ◽  
Grinding Wheels ◽  
Form Accuracy ◽  
Structured Surfaces ◽  
Milling Tool ◽  
Milling Tools

Micro milling tools made of PolyCrystalline Diamond (PCD) have been developed to machine ceramic micro dies and molds. Cutting edges are ground with diamond wheels. PCD milling tool wear is evaluated by cutting binder-less tungsten carbide spherical molds and machining structured surfaces for trial. Results of experiments clarified that PCD milling tool life is over 10 times that of resinoid diamond grinding wheels, and that form accuracy was 0.1 µm-0.3 µm P-V and surface roughness was 10 nm Rz.

Ultra Precision Grinding of Wafer Scale

2012 ◽  
Vol 516 ◽  
pp. 257-262
Author(s):  
Martin Hünten ◽  
Fritz Klocke ◽  
Olaf Dambon ◽  
Benjamin Bulla
Keyword(s):  
Tungsten Carbide ◽  
Surface Topography ◽  
Precision Grinding ◽  
Wafer Scale ◽  
Advantages And Disadvantages ◽  
Grinding Processes ◽  
Ultra Precision ◽  
Grinding Tool ◽  
Glass Optics ◽  
Grinding Machine

Manufacturing moulds for the wafer-scale replication of precision glass optics sets new demands in terms of grinding tool lifetime and the processes to be applied. This paper will present different approaches to grinding processes and kinematics to machine wafer-scale tungsten carbide moulds with diameters of up to 100 mm and more than 100 single aspheric cavities, each featuring form accuracies in the micron range. The development of these processes will be described and advantages and disadvantages of the approaches derived from practical tests performed on an ultra precision grinding machine (Moore Nanotech 350FG) will be discussed. Finally, a comparison between the developed processes is made where achieved form accuracies and surface topography are analyzed.

A Study of a New ELID Grinding Fluid by BP Neural Network Model

2011 ◽  
Vol 58-60 ◽  
pp. 1792-1796
Author(s):  
Wei Li ◽  
Yu Jie Fan
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Grinding Wheel ◽  
Precision Grinding ◽  
Elid Grinding ◽  
Environmental Friendly ◽  
Grinding Fluid ◽  
Hard And Brittle Materials ◽  
Ultra Precision ◽  
Bp Neural Network Model

Electronic in-process dressing (ELID) grinding will be a main technology of ultra-precision grinding which has been widely adopted to the ultra-precision and high effectively machining of hard and brittle materials. This study puts forward a new environmental friendly bamboo charcoal bonded (BCB) grinding wheel and develops a new ELID grinding fluid. An oxide layer is mostly determined by the electric performance of grinding fluid in the experiment. This paper founds a model to forecast grinding fluid’s electric performance by BP neural network and MATLAB. This method can be used in developing of ELID grinding machining fluid to improve the ELID grinding effect.

The Research of ELID Grinding Effect and Surface Quality on Carbonized Cold-Rolled Steel

2012 ◽  
Vol 229-231 ◽  
pp. 542-546
Author(s):  
J.L. Guan ◽  
Li Li Zhu ◽  
H.W. Lu ◽  
Zhi Wei Wang
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Grinding Wheel ◽  
Rolled Steel ◽  
Precision Grinding ◽  
Cold Rolled Steel ◽  
Elid Grinding ◽  
Peripheral Velocity ◽  
Ultra Precision ◽  
Cold Rolled

In this document, the electrolytic in-process dressing ( ELID ) grinding technique is used for ultra-precision processing experimental research on the carbonized cold-rolled steel (HRC60～80).A surface roughness of Ra6～8nm was obtained after ELID precision grinding. The results proved that adopting micro grain size (W1.5～W36) and high hardness cast iron based diamond grinding wheel, increasing the wheel peripheral velocity (18～20m/s) and reducing grinding depth can effectively improve surface quality and bring the surface roughness down. The wheel peripheral velocity, grinding depth as well as grinding fluid are the main factors during ultra-precision grinding.

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