• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.26-33
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• 2016

In this study, a new method to develop a fixed diamond wire for silicon wafer machining by the multi-wire cutting method was developed. The new twist diamond wire has improved performance with high breaking strength and chip flutes structure. According to these characteristics, the new twist diamond wire can be used in the higher speed multi-wire cutting process with a long lifetime. Except the design of the new structure, the twist diamond wire is coating by electroless-electroplating process. It is good for reducing breakage and the falling-off of diamond grains. Based on the silicon material removal mechanism and performance of the wire-cutting machine, the optimal processing condition of the new twist diamond wire has been derived via mathematical analysis. At last, through the tensile testing and the machining experiments, the performance of the twist diamond wire has been obtained to achieve the development goals and exceed the single diamond wire.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.38-42
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• 2001

A complete quantitative understanding of DT has been difficult because the process represents such a broad field of research. The experimental measurement of tool force is a single area of DT which still covers a wide range of possibilities. There are numerous parameters of the process which affect cutting forces. There are also many turnable materials of current interest. To obtain information toward a better understanding of the process, a few cutting parameters and materials were selected for detail study. It was decided that free-oxygen copper and 6061-T6 alloy aluminum would be the primary test materials. There are materials which other workers have also used because of there wide use in reflective applications. The experimental phase of the research project began by designing tests to isolate certain cutting parameters. The parameters chosen to study were those that affected the cross-sectional area of the uncut chip. The specific parameters which cause this area to vary are the depth of cut and infeed per revolution, or feedrates. Other parameter such a tool nose radius and surface roughness were investigated as they became relevant to the research.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.203-209
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• 1999

In this paper, we present the methods to predict the milled surface shapes in profile milling process. In the cutting process, tools are deflected due to the cutting forces varying with the imposed depth of cut and feedrate. Thus, the final shapes of the milled surface, generated by the nominal tool trajectory, are different from the required profile. In order to predict the milled surface shapes, we present two methods based on: (1) the deflected tool profile and (2) the trace of contact point between the tool and the workpiece. In the first method, we make an assumption that the milled surface corresponds to the deflected tool profile. In another method, we make we make an assumption that the milled surface is generated by the trace of the contact point between the cutting edge of the tool and workpiece. We present the surface generation process by calculating the trajectory of the contact points on the workpiece. Several simulations and experiments are performed to verify the proposed milled surface prediction methods.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.957-960
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• 1997

A complete quantitative understanding of DT has been difficult because the process represents such s broad field of research. The experimental measurement of tool force is a single area of DT which still covers a wide range of possibilities. Here are numerous parameters of the process which affect cutting forces. There are also many turnable materials of current interest. To obtain information toward a better understanding of the process, a few cutting parameters and materials were selected for detail study. It was decided that free-oxygen copper and 6061-T6 alloy aluminum would be the primary test materials. There are materials which other workers have also used because of there wide use in reflective applications. The experimental phase of the research project began by designing tests to isolate certain cutting parameters. The parameters chosen to study were those that affected the cross-sectional area of the uncut chip. The specific parameters which cause this area to vary are the depth of cut and infeed per revolution, or feedrates. Other parameter such a tool nose radius and surface roughness were investigated as they became relevant to the research.

• Journal of the Korea Furniture Society
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• v.19 no.5
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• pp.319-327
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• 2008

As art of lamination by plywood got to be generally used, it became a suitable material for expressing live curves that were not able to be expressed on wood furniture made of plank and timber, as well as, openwork deep in curved space, heavy quality of material, and changing contour line-looking wave lines with different process angles. As an alternative, it would be good to build a full scale model, since it would provide practice in form-building and it would also provide a chance to correct the form. Less material can be used and reduce the cutting process by Properly trimming models made of soft formal structure such as Styrofoam Iso-pink and adhesive Styrofoam, and separating the layers and using them on shape cutting of plywood with the same thickness. And by attaching the model veneer that was used in shape cutting of the model and using it as a cutting guide, we can reduce the error of work and successively build the planned form. Since this study is about the need of a full scale model for a laminated wood model and an efficient process, this study concentrates more on process.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.6
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• pp.83-89
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• 1999

This paper presents the in-process runout compensation methodology to improve the surface quality of circular contouring cut in end milling process. The runout compensation system is based on the manipulation of workpiece position relative to cutter in minimizing the cutting force oscillation at spindle frequency. the basic concept of this approach is realized on a end milling machine whose machining table accommodates a set of orthogonal translators perpendicular to the spindle axis. The system performed that measuring the runout related cutting force component, formulating PI controlling commands, and the manipulating the workpiece position to counteract the variation of chip load during the circular contouring cut. To evaluate the runout compensation system performance, experimental study based on the implementation of two-axes PI force control is presented in the context of cutting force regulation and part surface finish improvement.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.2
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• pp.20-26
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• 2013

This study focused on how it affects the surface roughness of work piece in cutting SCM415 steel, widely used steel in industry, by TiCN and TiN tools. Following conclusion was drawn from several experiments. The surface roughness of heat treated workpiece was better than that of non heat-treated materials. Moreover, the roughness of surface roughness(Ra 0.25) on feeding rate of 0.05 was better when it was in wet process, rather than dry process. As the feeding rate increases, TiCN coating tool shows better roughness of surface than TiN tool. Also, in heated treatment, TiCN coating tool shows the least straightness dimension deviation at feeding rate of 0.05, 0.15mm/rev, and concave-like R shape appears by the feeding rate orders of 0.05, 0.15, 0.1, 0.125 and 0.075mm/rev.

• Korean Journal of Computational Design and Engineering
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• v.7 no.3
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• pp.148-156
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• 2002

Most Rapid Prototyping (RP) processes adopt a solid Computer Aided Design (CAD) model, which will be sliced into thin layers of constant thickness in the building direction. Each cross-sectional layer is successively deposited and, simultaneously, bonded onto the previous layer; and eventually the stacked layers from a physical part of the model. A new RP process, the transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), has been developed to reduce building time and to improve the surface finish of parts with the thick layers and a sloping surface. This paper describes the generation of Unit Shape Layer (USL), the cutting path data of the linen. hotwire cutter for the VLM-ST process. USL is a three-dimensional layer with a thickness of more than 1 mm and a side slope, and it is the basic unit of cutting and building in the VLM-ST process. USL includes data such as layer thickness, positional coordinates, side angles of each layer, hotwire cutting speed, the heat input to the hotwire, and reference shape. The procedure of generating USL is as follows: (1)Generation of the mid-slice from the CAD model, (2)Conversion of the mid-slice into a simply connected domain, (3)Generation to the reference shape for the mid-slice, (4)Calculation of the rotation angle of the hotwire of the cutting system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.52-59
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• 2021

Titanium alloy (Ti-alloy) is widely used as a material for core parts of aircraft structures and engines that require both lightweight and heat-resistant properties owing to their high specific stiffness. Most parts used in aircraft have I-, L-, and H-shaped thin-walled structures for weight reduction. It is difficult to machine thin-walled structures owing to vibrations and deformations during machining. In particular, cutting tool damage occurs in the corners of thin-walled structures owing to the rapid increase in cutting force and vibration, and machining quality deteriorates because of deep tool marks on machined surfaces. In this study, milling experiments were performed to derive an effective method for machining a L-shaped thin-walled structure with Ti-alloy (Ti-6Al-4V). Three types of machining experiment were performed. The surface quality, tool wear, cutting force, and vibration were analyzed comprehensively, and an effective machining method in terms of tool life and machining quality was derived.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.6
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• pp.81-88
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• 2022

Titanium alloy (Ti-6Al-4V) has excellent mechanical properties and high specific strength; therefore, it is widely used in aerospace, automobile, defense, engine parts, and bio fields. Particularly in the aerospace field, as it has a low specific gravity and rigidity, it is used for the purpose of increasing energy efficiency through weight reduction of parts, and most have a thin-walled structure. However, it is extremely difficult to machine thin-walled shapes owing to vibration and deformation. In the case of thin-walled structures, the cutting forces and vibrations rapidly increase depending on the cutting conditions, significantly affecting the surface integrity and tool life. In this study, machining experiments on thin-wall milling of a titanium alloy (Ti-6Al-4V) were conducted for each experimental condition with different axial depths of cut, radial depth of cut, and machining sequence. The machining characteristics were analyzed, and an effective machining method was derived by a comprehensive analysis of the machined surface conditions and cutting signals.