• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.147-150
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• 1995

High speed machining one of the most effectiv to improve machining accuracy and product in dies and mould. But a study on this is limited to Alumium, light metal etc. This paper presents machining characteristic of gray cast iron in high speed machining with tungsten carbide endmill. It is suggested to measure sutting force, tool wear, surface roughness, surface shape and select of cptimal cutting condition in the high speed machining of gray cast iron. Performance of high speed machine tool was estimated and the relationship between cutting phenomenon and machinabillity was described.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.6
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• pp.513-519
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• 2014

For depth machining in die and mold, Electrical Discharge Machining (EDM) is used generally. To make deep hole and deep shape efficiently, cemented carbide endmill for depth machining is necessary. For this purpose, cemented carbide endmill was designed using design of experiment (DOE). To improve cutting performance, endmill was coated with multilayer surface treatment, TiAlCrSiN and TiAlCrN, for higher wear resistance. In order to evaluate the endmill, Transverse Rupture Strength (TRS) test was tried for investigating the relationship between surface treatment and strength in endmill body. Scratch test was also used for measuring adhesion force of each surface treatment. To evaluate hardness of surface treatment, Atomic Force Microscope (AFM) analysis was carried out. Wear test was executed for characteristics of each surface treatment in high temperature. Consequently, TiAlCrSiN was superior to the TiAlCrN coating in case of high temperature environment such as cutting.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.409-410
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.717-718
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• 2007

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.104-110
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• 2008

A lot of straight bevel gears have been manufactured by the cold forging process in order to improve the productivity and mechanical property of the product. The die for the cold forging of the gear needs high precision and reproducibility. In the study, cold forging die has been modeled by CAD/CAM and manufactured by machining center using ball end mill coated by (Al, Ti)N for heat-treated alloy steel(STD11, HRC 60). Through the measurement of the machined die, satisfactory dimensional accuracy and surface roughness were obtained. In the future, many 3-d cold forging dies will be directly machined instead of electric discharge machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.13-14
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• 2006

The quality of tool material is very important factor in machining evaluation. The characteristics of tungsten carbide, such as grain size and hardness, and density are depending on the variation of Co composition and WC size. In this study, the non-coated end mill which is made of ultra-fine tungsten carbide is investigated by measuring tool wear and tool lift test. The machining test is conducted with high hardened workpiece under high-speed cutting condition.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.865-869
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• 1997

In recent years, there has been increasing demand of ultra-fine grain graded cemented tungsten carbide material with high hardness and toughness which is used as high speed cutting tool for development in semiconductor, electronics and die/mold industry, which bring into limelight high-precision, high-efficient machining of sculptured surfaces. This paper deals with the performance of variation in the ultra-fine grain graded cemented tungsten carbide material such as grain size, hardness and density varied according to the volume of added elements, Co or TaC, and he changing of mixing, sintering process. Also, the performance of developing material with uniformed grain size of 0.5${\mu}{\textrm}{m}$ is compared with other domestics' & foreign companies' with analyzing and cutting performance testing.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.6
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• pp.1-8
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• 2007

The ultra-fine tungsten carbide(WC) powders have been actively used in the cemented carbides industry, because they have excellent mechanical properties such as high hardness, strength, and toughness. In this study, ultra-fine WC-Co alloys powders have been fabricated by thermochemical and thermomechanical process such as spray conversion process or high energy ball milling. The non-coated end-mill which is made of ultra-fine tungsten carbide is investigated by measuring cutting force, tool wear, tool life, and surface roughness profile according to cutting length. The machining test was conducted with high hardened workpiece and their performances are investigated in high speed cutting conditions. Also, the relationship between the machining characteristics and the Co contents are investigated under various high speed cutting conditions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.3
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• pp.92-99
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• 2022

Owing to the excellent corrosion resistance of titanium alloys, they are widely used as materials for aircraft components. However, in terms of machining, dimensional deformation methods vary significantly, such as forging, owing to their difficult-to-cut property and the uncontrollable vibration generated during machining. A method to minimize the vibration generated during machining by applying advanced tools and controlling the sequence of machining processes, which can improve the machinability and precision of titanium alloy-forged low-angle components, is proposed herein. Using the proposed tool and based on a process order experiment, the efficiency of the machining process is verified by measuring the dimensional deformation of the low-angle component.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.5
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• pp.34-39
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• 2022

The ion implantation technology changes the chemical state of the surface of a material by implanting ions on the surface. It improves the wear resistance, friction characteristics, etc. Plasma ion implantation can effectively reinforce a surface by implanting a sufficient amount of plasma nitrogen ions and using the injection depth instead of an ion beam. As plasma ion implantation is a three-dimensional process, it can be applied even when the surface area is large and the surface shape is complicated. Furthermore, it is less expensive than competing PVD and CVD technologies. and the material is The accommodation range for the shape and size of the plasma is extremely large. In this study, we improved wear resistance by implanting plasma nitrogen ions into a carbide end mill tool, which is frequently used in high-speed machining