• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.30-36
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• 2013

An FFD(flexible fine die) is an embossed mold that consists of a thin plate ranging from 0.6 to 3 mm in thickness. FFDs are primarily used for cutting LCD films and F-PCB sheets. In the high-speed micro-milling process of flexible fine dies, the lubrication and cooling of the cutting edges is very important from the aspect of eco machining and cutting performance. In this paper, a comparative study of tool wear and surface roughness between cutting fluid and hybrid lubrication for eco-machining of FFD was conducted for processes of high-speed machining of highly hardened material (STC5, HRC52). Especially, the incorporated fluid method for eco machining, in which the cutting performances can be simultaneously measured, was introduced. The machining results show that hybrid lubrication, instead of conventional cutting fluid, leads to excellent tool wear and surface roughness and represents the proper conditions for eco micro-machining of flexible fine dies.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.81-88
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• 2016

Recently, high-efficiency machining in the production of high-value products with complex shapes has constantly been required along with the need for hybrid machining. In this study, in addition to wire-cut Electric Discharge Machining (EDM) and vibration, we present the possibility of a hybrid process by carrying out an experiment with aluminum alloy, and the hybrid process determines the nature of the surface. The selected experimental parameters are waveform, amplitude, peak current, and two-dimensional (2D) vibration. The experimental results give the guideline for selecting reasonable machining parameters. The surface roughness was improved about 20% with increases in the amplitude of the vibration.

• Journal of Powder Materials
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• v.20 no.4
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• pp.297-301
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• 2013

Mirror surface machining for large area flattening in the display field has a problem such as a tool wear and a increase in machining time due to large area machining. It should be studied to decrease machining time and tool wear. In this paper, multi-tool machining method using a PCD tool and a SCD tool was applied in order to decrease machining time and tool wear. Machining characteristics (cutting force, machined surface and surface roughness) of PCD tool and SCD tool were evaluated in order to apply PCD tool to flattening machining. Based on basic experiments, the PCD/SCD multi-tool method and the SCD single-tool method were compared through surface roughness and machining time for appllying large area mold machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.338-342
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• 2003

Hybrid machine is based on hardware technologies of machine tool and software technologies of open architecture controller. In machining technology, combination technology of turning, milling, and grinding and in machining energy technology. combination of mechanical, electrical, and chemical technology are developed. This paper describes hybrid machine technology for combination of machining, on-machine measurement, on-machine CAM, and on-machine remote monitoring and control in open architecture controller environment. For on-machine measurement, non-contact measurement technology based on CAD information is developed. For on-machine CAM, interactive CAM program for automatic NC program generation and tool path simulation is developed. For generation on-machine remote monitoring and control, suitable interface method between web program and CNC is proposed. The developed hybrid machine technology is implemented in 3 axes milling machine for evaluation of operablity.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2256-2261
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• 2017

Carbon nanotube (CNT) and alumina ($Al_2O_3$) are synthesized into hybrid composites, and an advanced electrical discharge machining (EDM) system is developed for the machining of hard and conductive materials. CNT nanoparticles are mixed with $Al_2O_3$ powder and the $Al_2O_3$/CNT slurry is sintered by spark plasma. The hardness and the electrical conductivity of the $Al_2O_3$/CNT hybrid composite were investigated. The electrical discharge is controlled by a capacitive ballast circuit. The capacitive ballast circuit is applied to the tungsten carbide and the $Al_2O_3$/CNT hybrid composite. The voltage-current waveforms and scanning electron microscope (SEM) images were measured to analyze the characteristics of the boring process. The developed EDM process can manufacture the ceramic based hybrid composites, thereby expecting the variety of applications.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.100-107
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• 2015

Recently, high-efficiency machining in the production of high-value products with a complex shape has constantly been required with the need for hybrid machining. In this study, in addition to the wire-cut E.D.M. and vibration used to present the possibility of a hybrid process by carrying out the aluminum alloy experiment, the hybrid process determines the nature of the surface. The selected experimental parameters are horizontality, waveform, amplitude, peak current, and frequency. The experimental results give guidelines for selecting reasonable machining parameters. The surface roughness was improved by about 20% with increases in the amplitude of the vibration.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.10
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• pp.1089-1095
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• 2012

Laser beam machining (LBM) using nanosecond pulsed laser is widely known to be rapid and non-wear process for micromachining. However, the quality itself cannot meet the precision standard due to the recast layer and heat affected zone. In this paper, a fabrication method for machining micro features in stainless steel using a hybrid process of LBM using nanosecond pulsed laser and electrochemical etching (ECE) is reported. ECE uses non-contacting method for precise surface machining and selectively removes the recast layer and heat affected zone produced by laser beam in an effective way. Compared to the single LBM process, the hybrid process of LBM and ECE enhanced the quality of the micro features.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1865-1868
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• 2003

This paper provides a new method for hybrid machining, particularly suited to micro fabrication applications such as micro point, micro line, micro structure, micro partition and so on. Developed micro fabrication process by electrical discharge machining (EDM) and electrical discharge deposition (EDD) with metal powder (Ti, Fe) has been studied to build TiC or FeC structure. Titanium powder or iron powder is supplied from working fluid (kerosene or de-ionized water with powder) and adheres on a workpiece by the heat and electric power caused by the electrical discharge. The use of a tool electrode is expected to keep powder concentration high in the gap between a workpiece and a tool electrode and to accrete powder material on the workpiece. The deposition is tried under various electrical conditions (workpiece. tool electrode, working fluid, discharge current, voltage and powder etc.). On the other hand. using electrical discharge machining (EDM) with the same tool electrode, it can be used as a removal process (cutting) by electro erosion at the same time. Therefore. this new method can do a hybrid machining to build up and down a structure with the workpiece.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.3
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• pp.28-35
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• 2013

Micro electrical discharge machining (EDM) as a non-contact machining process is very effective for micromachining with a thin electrode because of its low machining reaction force. The micro-electrode machining device has the advantage of maintaining high precision through the whole processes and uses a feeding wire in the thin electrode tool manufacturing process. This study describes the design and evaluation of a micro-electrode machining device using optical photo-interrupter. The electrode was fabricated by reverse electrical discharge machining. The performance of designed system was evaluated to measure tension force according to feed speed of wire. This system for micro electrode fabrication proves the feasibility in the micro-EDM process of the micro holes and parts for industrial applications.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.9
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• pp.7-13
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• 2008