• Journal of the Korean Society for Precision Engineering
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• v.18 no.5
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• pp.130-136
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• 2001

Generally, a metal slitting saw is plain milling cutter with thickness less than 3/16 inch. This is used for cutting a workpiece that high dimensional accuracy and surface finish is necessary. A small thin milling cutter like a metal slitting saw is useful for machining a narrow groove. In this case, built up edge(BUE) is severe at each tooth and affects the surface integrity of the machined surface and tool wear. It is well known that tool geometry and cutting conditions are decisive factors to remove BUE. In this paper, we optimized the geometry of the milling cutter and selected cutting conditions to remove BUE by the experimental investigation. The experiment was planned with Taguchi method based on the orthogonal array of design factors such as coating, rake angle, number of tooth, cutting speed, feed rate. Response table was obtained from the number of built-up edge generated at tooth. The optimized tool geometry and cutting conditions could be determined through response table. In addition, the relative effect of factors was identified bh the analysis of variance (ANOVA). Finally, coating and cutting speed turned out important factors for BUE.

• Journal of the Korean institute of surface engineering
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• v.33 no.4
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• pp.222-228
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• 2000

The life time of cutting tool was studied in the relation with the properties of TiN coating tools. The purpose of this study is to compare the cutting conditions of the TiN coated tools with those of the non-coated tools and to find out the optimal cutting condition of the TiN coated tool. The coated tools were prepared by the sputtering process at $4$\times$10^{-3}$Torr. When the cutting speed is increased 22.2% from 90m/min, the limited life of coating bite was decreased by 60.61%, but non-coating bite was decreased by 64.05%. In the tool lifetime equation of the coated tools "a"(exponent of feed rate) was not much changed in comparison with that of the non-coated tools but "n" (exponent of tool′s life) was increased by 9.3% and "b" (exponent of cutting depth) was increased by 2.4%. It was thought to be that TiN coated tools was used for higher cutting speed than non-coated tools to improve the lifetime of the coated tools.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.45 no.4
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• pp.61-69
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• 2022

The function of coolant in machining is to reduce the frictional force in the contact area in between the tool and the material, and to increase the precision by cooling the work-piece and the tool, to make the machining surface uniform, and to extend the tool life. However, cutting oil is harmful to the human body because it uses chlorine-based extreme pressure additives to cause environmental pollutants. In this study, the effect of cutting temperature and surface roughness of titanium alloy for medical purpose (Ti-6Al-7Nb) in eco-friendly ADL slot shape machining was investigated using the response surface analysis method. As the design of the experiment, three levels of cutting speed, feed rate, and depth of cut were designed and the experiment was conducted using the central composite planning method. The regression expressions of cutting temperature and surface roughness were respectively obtained as quadratic functions to obtain the minimum value and optimal cutting conditions. The values from this formula and the experimental values were compared. As a result, this study makes and establishes the basis to prevent environmental pollution caused by the use of coolant and to replace it with ADL (Aerosol Dry Lubricant) machining that uses a very small amount of vegetable oil with high pressure.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.129-136
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• 2012

This study was conducted to develop an efficient mass propagation method for the mature $Prunus$ $yedoensis$ Matsumura (43 to 58 years old). Cutting was conducted depending on cutting time, auxin treatments (IBA and NAA treatments mixed with talc powder), and cuttings position on shoots in a plastic house equipped with a fog system without heating. Rooted cuttings were transplanted to a nursery bed, and their growth characteristics were investigated in order to check whether the cuttings are successful or not for roadside tree planting. The average rooting rate was highly significant ($P$ < 0.0001) in all treatments: cutting on June 1st (61.4%) was more than two times greater in rooting rate than that on August 1st (23.6%); IBA 1,000 $mg{\cdot}L^{-1}$ (90.8%) and IBA 500 $mg{\cdot}L^{-1}$ (89.2%) showed much greater rooting rates than those of the other treatments; upper part of the cuttings treated with IBA 1,000 $mg{\cdot}L^{-1}$ showed the highest rooting rate, 96.7%. The interactions among treatments in the average rooting rate were also significant. There were significant differences ($P$ < 0.0001) among the auxin treatments in the survival rate of leafed cuttings transplanted to a nursery bed. The average survival rate was 46.5%, and IBA 1,000 $mg{\cdot}L^{-1}$ treatment was the highest in leafed cuttings 79.2%, but most of leafless cuttings were dead. There were significant differences ($P$ < 0.0001) among the cuttings, grafts, and in the seedlings height, diameter at root collar, the number of roots, branches, and leaves, etc., and the cuttings was the best. We can expect a possibility of mass propagation of improved $P.$ $yedoensis$ Matsumura and a high planting survival rate through the transplanting of cuttings to a nursery bed in which the cuttings should be the following conditions: cutting in June to July, use of the upper part of cuttings, IBA treatment, and rooting in August in a cutting-greenhouse equipped with a fog system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.2
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• pp.153-170
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• 2022

Waterjet has been comprehensively used in urban areas owing to a suitable technique for cutting concrete and rock, and low noise and vibration. Recently, the abrasive waterjet technique has been adopted and applied by the Korea Atomic Energy Research Institute to demolish concrete plugging without disturbing and damaging In-situ Demonstration of Engineered Barrier System in the disposal research tunnel. In this study, the use of abrasive waterjet in the tunnel was evaluated for practical applicability and the existing cutting model was compared with the experimental results. As a variable for waterjet cutting, multi-cutting, water flow rate, abrasive flow rate, and standoff distance were selected for the diversity of analysis. As regarding the practical application, the waterjet facilitated path selection for cutting the concrete plugging and prevented additional disturbances in the periphery. The pump's noise at idling was 64.9 dB which is satisfied with the noise regulatory standard, but it exceeded the standard at ejection to air and target concrete because the experiment was performed in the tunnel space. The experimental result showed that the error between the predicted and measured cutting volume was 12~13% for the first cut and 16% for second cut. The standoff distance had a significant influence on the cutting depth and width, and the error tended to decrease with decrement of standoff distance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.1 no.1
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• pp.133-140
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• 2002

The object of this paper is to predict the surface roughness using the experiment equation of surface roughness, which is developed with a full factorial design in turning. $3^3$ full factorial design has been used to study main and interaction effects of main cutting parameters such as cutting speed, feed rate, and depth of cut, on surface roughness. For prediction of surface roughness, the arithmetic average (Ra) is used, and stepwise regression has been used to check the significance of all effects of cutting parameters. Using the result of these, the experimental equation of surface roughness, which consists of significant effects of cutting parameters, has been developed. The coefficient of determination of this equation is 0.9908. And the prediction ability of this equation was verified by additional experiments. The result of that, the coefficient of determination is 0.9718.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.317-322
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• 2004

This paper deals with a prediction method of tool life in view of the reliability assessment. In this study, the flank wear was studied among multi-factors deciding the tool wear state. Firstly, tool lift was predicted by correlation between flank wear and cutting time, based on the extended Taylor tool life equation of turning data, including parameters of cutting speed, feed rate, and cutting depth. Secondly, each of cutting conditions of endmilling was equivalently converted to apply ball endmill data to the extended Taylor equation. The web-based reliability prediction program for tool lift is being developed as one of reliability assessment programs to for the machine tools.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.57-63
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• 2011

The aim of this study is to analyze turning process using commercial FEM simulation code. Various simulation models of orthogonal cutting process for 3 layers of metallic material have been simulated and analyzed. The workpiece material used for the orthogonal plane-strain metal cutting simulation consists of three layers, which are Allow Tool Steel, Aluminum and Stainless Steel. The finite element model is composed of a deformable workpiece and a rigid tool. The tool penetrates through the workpiece at a constant speed and constant feed rate. As an analytical result, detailed cutting temperature, strain, pressure, residual stress for both a tool and each layer of workpiece were obtained during the turning process. It has been closely observed that the chip flow curve deforms continuously.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.538-541
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• 2003

Ultra-precision machining was carried out on a electroless nickel materials using single crystal diamond tools. The effects of the cutting velocity, the tool length, the tool nose radius, the feed rate and depth of cut on the surface roughness were studied. In this paper, the cutting condition for getting nano order smooth surface of electroless nickel have been examined experimentally by the ultra-precision machine and single crystal diamond tools. And also. the surface roughness was measured by the three dimension

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.6
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• pp.36-43
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• 2003

In machining of ceramic materials, they are very difficult-to cut materials because of there high strength and hardness. Machining of ceramics are characterized by cracking and brittle fracture. Generally, ceramics are machined using conventional method such as finding and polishing. However these processes are generally costly and have low MRR(material removal rate). This paper focuses on determining the optimal levels of process parameters for products with CNC machining center. For this purpose, the optimization of cutting parameters is performed based on experimental design method. A design and analysis of experiments is conducted to study the effects of these parameters on the surface roughness by using the S/N ratio, analysis of ANOVA and F-test. Cutting parameters, namely, cutting speed, feed and depth of cut are optimized with consideration of the surface roughness.