• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 춘계학술대회 논문집
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• pp.75-79
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• 1995

A cutting experiment using diamond tool was performed to make the die cabity which is composed of micro groove with mirror surface. Fine cutting depth was generated by the elastic recovery of the modified tool holder on the conventional M/C. Surface roughness and profile were investigated with cutting speed and depth and through the low cutting speed of 10mm/min, Rmax 0.005 .mu. m or less of machined surface could be achieved.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.135-139
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• 1996

In this a paper, a new method to measure the wear of the single crystal diamond(SCD) tool using image processing is presented. To increase resoultion, high magnifying lens is used and to enlarge the measurement field of view, a image region matching method is applied. The shape of SCD tool is modeled by mathematical analysis. Cutting edge chipping and wear are calculated by the model. This method is proved to be efficient in detecting a few micron of wear and cutting edge loss by chipping along the whole cutting edge.

• Journal of Mechanical Science and Technology
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• 제17권2호
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• pp.239-245
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• 2003

Ultra precision diamond cutting is a very efficient manufacturing method for optical parts such as HOE, Fresnel lenses, diffraction lenses, and others. During micro cutting, the rake angle is likely to become negative because the tool edge radius is considerably large compared to the sub-micrometer-order depth of cut. Depending on the ratio of the tool edge radius to the depth of cut, different micro-cutting mechanism modes appear. Therefore, the tool edge sharpness is the most important factor which affects the qualities of machined parts. That is why diamond, especially monocrystal diamond which has the sharpest edge among all other materials, is widely used in micro-cutting. The majar issue is regarding the minimum (critical) depth of cut needed to obtain continuous chips during the cutting process. In this paper, the micro machinability near the critical depth of cut is investigated in micro grooving with a diamond tool. The experimental results show the characteristics of micro-cutting in terms of cutting force ratio (Fx/Fy), chip shape, surface roughness, and surface hardening nea. the critical depth of cut.

• 한국정밀공학회지
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• 제25권3호
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• pp.56-62
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• 2008

The biocompatibility and the fatigue strength of Co-Cr-Mo alloy are excellent, so it is used well for the material of artificial joints. The head of artificial joint needs mirror surface for reduction of abrasive resistance. Mirror finishing of Co-Cr-Mo alloy with geometrically defined single crystal diamond cutting tools is handicapped by micro chipping of tool edge. In general, it is said that the micro chipping of diamond tool is caused by work hardening of Co-Cr-Mo alloy for the cut. In the present research, mirror finishing of Co-Cr-Mo alloy by applying ultrasonic elliptical vibration cutting was carried out. The experimental results show that the micro chipping of diamond tool was suppressed and the tool wear was remarkably reduced as compared with the ordinary diamond cutting without elliptical vibration motion. It was confirmed that the good mirror surface of maximum surface roughness of 25 nmP-V was obtained for the cutting length of about 14 m. It is expected that mirror finishing of Co-Cr-Mo alloy can be achieved by applying ultrasonic elliptical vibration cutting practically.

• 한국세라믹학회지
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• 제30권5호
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• pp.420-426
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• 1993

The machinability of ceramics has been experimentally studied. The experiments were conducted on alumina cernmics of various purity, quartz, and cordierite using the sintered diamond tools and CBN tools. Tool wasre, surface roughness, and cutting resistence were measured and analysed. It was found that the workpieces could be machined with the diamond and CBN tools, but the sintered diamond tools were more efficient for the machining of the high strength ceramics. The machining of alumina ceramics with sintered diamond tools showed that (1) wet machining prolonged tool life comparing with dry machining, (2) workpiecewith higher purity had better surface roughness, (3) severe cutting conditions led to the chipping and fracture of tool and increase of the surface roughness and cutting resistance, (4) 20~40m/min of cutting speed, 0.01~0.02mm/rev of feed, and 0.1~0.2mm of cutting depth are suggested as proper cutting conditions for the high strength ceramics.

• 한국정밀공학회지
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• 제31권3호
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• pp.207-213
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• 2014

A study was carried out to fabricate the cutting tool geometry with micro/nanoscale on the single crystal diamond tool by using the FIB. The FIB technique is an ideal tool for TEM sample preparation that allows for the fabrication of electron-transparent foils. The FIB is appropriate techniques to sample and subsequently define the chemical composition and the structural state of mineral inclusion on the micro/nanoscale. The combination of FIB with a SEM allows for 3D information to be obtained from samples including 3D imaging. Cutting strategies were demonstrated to improve the performance of cutting tool geometry and to generate high aspect ratio micro cutting tool. A finely focused beam of 30keV Ga+ ions was used to mill cutting tool shapes for various micro patterns. Therefore FIB sputtering is used to shape a variety of cutting tools with dimensions in the $1-5{\mu}m$ range and cutting edge radii of curvature of under 50nm.

• 한국정밀공학회지
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• 제15권3호
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• pp.141-149
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• 1998

Diamond shaping is one of the machining strategies to make the optical micro-groove molds, and it is especially useful when the component is an assembly of the linear micro-groove array. A mirrorlike surface and an arbitrary crose-sectional curve can be easily made by the diamond tool. However, the cutting speed of shaping is relatively lower than that of the other cutting methods, and there exist an unstable cutting conditions that generate the chatter. This study is focused on the modeling of the simplified self-induced chatter of the diamond shaping, and the machinabilities of three materials are compared by cutting experiments. From the chatter model and experiments, it is found that the unstable cutting conditions exist when the depth of cut is low and cutting speed is high. It is also found that the brass is relatively good material in micro shaping than copper or aluminium from the cutting experiments.

• The Korean Journal of Ceramics
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• 제2권4호
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• pp.203-211
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• 1996

CVD diamond tools are becoming more widely used in industry as an economic alternative to polycrystalline diamond (PCD) for machining non-ferrous and non-metallic materials. Although CVD diamond-sheet tools have been on the market for several years, diamond-coated carbide inserts have become available only recently, with the successful resolution of long-standing adhesion problems. Diamond coating morphology on the rake surface of the tool affects chip formation favorably, whereas a microscopically rough, faceted morphology on the flank surface of the tool produces a rough workpiece finish. Workpiece finish can be improved by using a coated tool with a larger nose radius. The tool life provided by diamond-coated tools(~30 $\mu\textrm{m}$ thick) can meet or exceed that of PCD tools, depending on the characteristics of the workpiece material. When using diamond-coated carbide tools in milling, a sharp-edged PCD tool should be used in the wiper position of the cutter to minimize workpiece roughness and burr formation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.980-983
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• 2002

In micro-machining, diamond tool is commonly used because it brings much better micro-machinability due to its edge sharpness. However, it is a big question even how thinly the sharp edge of a diamond tool can cut a ship from the workpiece surface. This paper is to investigate the critical cutting depth, at which the dominant cutting mode changes from chip formation to burnishing or vice versa, for a given edge radius. The theoretically critical cutting depth is 0.25$\mu\textrm{m}$(0.8$\mu\textrm{m}$) in cutting using a square type(V-type) diamond tool that has edge radius of 1$\mu\textrm{m}$(1.5$\mu\textrm{m}$). Experimentally, the dominant cutting mode changes and cutting surface becomes better at critical cutting depth. To get high quality surface, depth of cut must be critical cutting depth because less plastically deformed substrate is left on the surface.

• 한국생산제조학회지
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• 제9권1호
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• pp.75-80
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• 2000

This paper deals with the precision cutting characteristics of mono-crystal diamonds poly-crystal diamonds and tungsten carbide tool on ductile material. The cutting tests were carried out under various uncut chip areas and 20${\mu}{\textrm}{m}$ depth of engagement. The machinability in precision machining was discussed from the viewpoints of the normal cutting forces and the surface roughness of the workpiece. As the feed rate decreases the normal force difference for cutting edge radii appears to large. In various cutting edge radii the surface roughness difference when cut the copper which is ductile material than the aluminium alloy is large. As the same cutting condition the hardness value on cut surface with the diamond tool appears to be smaller than that of the tungsten carbide tool.