• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1902-1906
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• 2003

Micro-milling is an efficient method for fabricating micro structures because of its high machining rate compared with other non-conventional micro machining processes. But it is not easy to make a micro milling tool with less than 50 $\mu\textrm{m}$ in diameter by conventional machining. In this study, the characteristics of a micro milling tool fabricated by wire electrical discharge machining (WEDM) were studied. The workpiece is copper and stainless steel. The effects of some machining conditions such as feed rate, depth of cut, and a shape of tool were studied. The tools with D-shape and square shape in cross section were tested for machining micro grooves and 3D structures.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1875-1878
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• 2005

It is not efficient and scarcely out of the question to use commercial expensive electron beam lithography system widely used for semiconductor fabrication process for the manufacturing application field of various devices in the small business scope. Then scanning electron microscope based electron beam machining system is maybe regarded as a powerful model can be used for it simply. To get a complete suite of thus proper system, column unit build up with electron beam gun head unit is necessarily required more than anything else to modify scanning electron microscope. In this study, various components included ceramic isolation plate and main body which are essentially constructed for electron beam gun head unit are designed and manufactured. And this electron beam gun head unit will be used for next connected study in the development step of scanning electron microscope based electron beam machining system.

• 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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.16-21
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• 2002

The high speed machining center(HMC) has been widely applied to manufacture a die and trial product in many machine industry. Because the evaluation fer the HMC is not sufficiently performed and the efficient cutting conditions aren't selected, a great loss has been caused in the cost aspect. In this study, the need of preliminary running time and unstable spindle speed is presented from the analysis of acceleration in idling. The Machinability fur the TiAlN coated flat end mill and STD11( $H_{R}$C60) is evaluated from the trends of tool wear and cutting force according to cutting conditions and slenderness ratio and a low response of tool dynamometer in high speed is proved. The resonance spindle speed is identified through the tool wear and natural frequency test.t.

• 한국생산제조학회지
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• 제21권6호
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• pp.982-987
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• 2012

Inconel 718 alloy has been widely used in the aerospace, heavy industry and electronic industry. However, the machinability of this alloy is very poor, which is attributed to their inherent high strength that is maintained at elevated temperatures. The tool life is dominant problem in machining difficult-to-cut materials, so it is necessary to select the efficient cutting conditions for the improvement of tool life. In this study, the cutting force, tool wear and surface roughness are investigated in end milling machining under various cutting conditions. By this experiment, the efficient machining condition of this alloy is suggested to adopt in various industries.

• 한국정밀공학회지
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• 제18권2호
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• pp.84-89
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• 2001

In recent years, there is increasing demand of esthetic design and complex function in aerospace, automobile and die/mold industry, which brings into limelight high-precision, high-efficient machining of sculptured surface. This paper deals with the establishment of the optimal tool path on free form surface in high speed ball end milling. Ball end milling is widely used for free form surface die and mold. In this machining, the cutting direction was changed with tool path. The cutting characteristics, such as cutting force and surface form are varied according to the variation of cutting directions. In this paper, the optimal tool path with down cutting in free form surface cutting is suggested.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.424-429
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• 2004

The high speed machining center(HMC) has been widely applied to manufacture a die and trial product in many machine industry. Because the evaluation for HMC is not sufficiently performed and the efficient cutting conditions can't be selected, a peat loss has been caused in the cost aspect. In this study, the need of preliminary running time and unstable spindle speed is presented by the analysis of acceleration in idling. The Machinability for the TiA1N coated flat end mill and STD11 (H$\sub$R/C60) is evaluated from the trends of tool wear and cutting force according to cutting conditions . The resonance spindle speed is identified through the tool wear and natural frequency test.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.379-382
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• 2004

Abrasive jet machining (AJM) has a large number of parameters such as powder flow rate, air pressure, diameter of abrasive, stand off distance, material hardness and fracture toughness, etc. It is not easy matter to control those parameter. To achieve high accurate machining, in this study, Taguchi method was used to select process parameters. The objective of the optimization was to get higher material removal rate (MRR). From the experiments and analysis, some process parameters were found to make efficient machining.

• 한국정밀공학회지
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• 제15권2호
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• pp.14-20
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• 1998

Automatic finishing process requires the development of high efficient and precision abrasive machining method for dies and molds. This study describes the evaluation of the finishing characteristics, such as surfrace roughness, topography and material removal depth of the electrolytic mixed abrasive machining methods. Experimental setup is composed of 3 axis machining center, a newly developed finishing attachment with constant pressure, electrode and electrolytic bath. Finally, we achieved a successful result that surface roughness is $0.01\mu$m Ra and material removal depth is $120\mu$m using electrolytic(0.8A. 30V) mixed abrasive (#400 CBN, #320 SiC) machining method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.937-941
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• 1997

Utomatic finishing process requires the development of high efficient and precision abrasive machining method for die and molds. This study describes the evaluation of the finishing characteristics, such as sufrace roughness, topography and material removal depth, of the electrolytic chemical mixed abrasive machining method. Experimental setup is composed of 3 axis machining center, a newly developed finishing attachment with constant pressure, electrode and electrolytic bath. Finally, we achieved a successful result that surface roughness is 0.01 .mu. m Ra and material removal depth is 145 .mu. m after 100 times repeat-finishing using electrolytic (0.8A,30V) mixed abrasive (#400 CBN, #320 Sic) machining method.