• Journal of the Korean Society for Precision Engineering
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• v.33 no.5
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• pp.385-392
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• 2016

Recently in the display industry, demands for high-luminance and resolution of display devices have been steadily increasing. Generally, micro linear patterns are applied to an optical film in order to improve its properties of light. However, these patterns are easily viewed to eyes and moire phenomenon can be occurred. Micro random patterns are proposed as a method to solve these problems, increasing light-luminance and light-diffusion. However, conventional pattern manufacturing technologies have long processing times and high costs making it difficult to apply to large area molds. In order to combat this issue, micro-random patterns are formed by using a roll to plate indentation method along with abrasive paper tools composed of AlSiO2, SiC, and diamond grains. Also, forming properties, such as size and fill-factor of random patterns, are analyzed depending on type, mesh of abrasive paper tools, and indentation forces.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.24-31
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• 2004

The objective of this work is to suggest a mastless pattern fabrication technique using the combination of machining by Nanoindenter(equation omitted) XP and HF wet etching. Sample line patterns were machined on a borosilicate surface by constant load scratch (CLS) of the Nanoindenter(equation omitted) XP with a Berkovich diamond tip, and they were etched in HF solution to investigate chemical characteristics of the machined borosilicate surface. All morphological data of scratch traces were scanned using atomic force microscope (AFM).

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2006.04a
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• pp.55-55
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• 2006

• Journal of the Korean Society for Precision Engineering
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• v.19 no.1
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• pp.18-24
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• 2002

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.140-140
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• 2009

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.115-121
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• 2007

Phase contrast imaging in atomic force microscopy showed a promise as an effective tool for better understanding of micromechanical properties of surfaces at nano scale. A qualitative estimation model for phase contrast images obtained with a tapping mode AFM was developed. This investigation demonstrated the high efficiency of combined analysis of topography and phase contrast images for characterizing nanosurfaces. Phase contrast images allowed estimation of relative stiffness(elastic modulus) of the sample surface. The phase contrast images revealed a significant inhomogeneity of the nano scale worn surfaces. Phase contrast images are also capable of revealing the formation of tribofilms.

• Journal of Industrial Technology
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• v.14
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• pp.119-125
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• 1994

Ultra-precision machine tool equipped with the diamond bite tip is used to machine optical products, drums of VTR or computer hard disk. It needs nano technology in the surface roughness of workpiece. To perform the nano scale machining, ultra-precision machine tool must be designed and manufactured in consideration of the vibration characteristics. In this paper, using the finite element analysis, we investigate the modal parameters of the ultra-precision machine tool structures, which use cast iron, granite and alumina ceramic for the bed materials. To verify the numerical results, we manufacture a model of ultra-precision machine tool using granite bed and perform impulse test. Through the theoretical and experimental analyses, we could compare and estimate the vibration characteristics of the three models for the ultra-precision machine tools.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.1
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• pp.76-82
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• 2009

To obtain the surface roughness with nano order, we need a ultra-precision machine, cutting condition, and materials. In this paper, the cutting condition for getting nano order smooth surface of core have been examined experimentally by the ultra-precision machine and diamond wheels. The effects of the cutting velocity, the feed rate and depth of cut on the surface roughness were studied. And also, the surface roughness was measured by the Form Talysurf series PGI 840. The champion data of developed core was surface roughness Rmax 24.6nm, figure accuracy Rmax 68.9nm.

• Transactions of Materials Processing
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• v.12 no.7
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• pp.623-630
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• 2003

Nanomachining process, static nanoplowing, is one of the most promising lithographic technologies in terms of the low cost of operation and variety of workable materials. In nanomachining process, chemical effects are more dominant factor compared with those by physical deformation or fracture. For example, during the nanoscratch on a silicon surface in the atmosphere, micro protuberances are formed due to the mechanochemical reaction between diamond tip and the surfaces. On the contrary, in case of chemically stable materials, such as ceramic or glass, surface protuberances are not formed. The purpose of this study is to understand effects of the mechanochemical reaction between tip and surfaces on deformation behaviors of hard-brittle materials. Nanometerscale elasoplastic deformation behavior of single crystal silicon (100) was characterized with micro protuberance phenomena, and compared with that of borosilicate (Pyrex glass 7740). In addition, effects of the silicon protuberances on nanoscratch test results were discussed.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.438-444
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• 2003

A new method to measure residual stress in micron and nano scale films is described. In the theory it is based on Linear Elastic Fracture Mechanics. And in the techniques it depends on the combined capability of the focused ion beam (FIB) imaging system and of high-resolution digital image correlation (DIC) software. The method can be used for any film material (whether amorphous or crystalline) without thinning the substrate. In the method, a region of the film surface is highlighted and scanning electron images of that region taken before and after a long slot, depth a, is introduced using the FIB. The DIC software evaluates the displacement of the surface normal to the slot due to the stress relaxation by using features on the film surface. To minimize the influence of signal noise and rigid body movement, not a few, but all of the measure displacements are used for determining the real residual stress. The accuracy of the method has been assessed by performing measurements on a nano film of diamond like carbon (DLC) on glass substrate and on micro film of aluminum oxide thermally grown on Fecrally substrate. It is shown that the new method determines the residual stress ${\sigma}_R=-1.73$ GPa for DLC and ${\sigma}_R=-5.45$ GPa for the aluminum oxide, which agree quite well with ones measured independently.