• 한국생산제조학회지
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• 제20권1호
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• pp.86-95
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• 2011

Ultra-precision machining technology is the essential core technology in today's micro-electronics and electro-optical industries. The needs for processing systems to manufacture products to nanometer(nm) accuracy and sub-nanometer resolutions are increased recently. By using ion beam, it is possible to fabricate ultra-precision and ultra-fine products with nm accuracy and sub-nm resolution. In this paper, the basic research trends of ultra precision machining technology in domestic are surveyed, and the ways to reach to the world-leading level of basic research capabilities in the field of ultra-precision machining technology in domestic is suggested.

• 한국레이저가공학회지
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• 제14권2호
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• pp.17-23
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• 2011

Active thin films are ubiquitous in the manufacture of all forms of flat panel display (FPD). One of the most widely employed thin films is indium tin oxide (ITO) and metal films used electrically conductive materials in display industries. ITO is widely used for fabrication of LCD, OLED device, and many kinds of optical applications because of transparency in visible range and its high conductivity and metal films are also widely employed as electrodes in various electric and display industries. It is important that removing specific area of layer, such as ITO or metal film on substrate, to fabricate and repair electrode in display industries. In this work, we demonstrate efficient selective ablation process to ITO and aluminum film on glass using a femtosecond laser (${\lambda}p=1025nm$) respectively. The femtosecond laser with wavelength of 1025nm, pulse duration of 400fs, and the repetition rate of 100kHz was used for selectively removing ITO and Al on glass in the air. We can successfully remove the ITO and Al films with various pulse energies using a femtosecond laser.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.75-78
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• 2007

Recently, the need for micro mold or micro mechanical parts has been rapidly increased. As feature size decreases, conventional machining processes show their limitation. Micro electrical discharging machining (EDM) and electrochemical machining (ECM) have many advantages in micro machining. They can be used to make structures of micro scale, or even nano scale size. In this paper, the application of micro EDM and ECM has been investigated.

• 한국기계가공학회지
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• 제10권6호
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• pp.22-26
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• 2011

The application of fast tool servo (FTS) for diamond turning has been investigated extensively. This paper focuses on the fabrication of the sinusoidal microstructure on a roller, which generated by a piezoelectric-assisted FTS. The influence of the machining parameters on the microstructure configuration was investigated. The experiment results point out that the configuration of the machined microstructure depends mainly on the spindle speed, the diameter of roller and the driving frequency of FTS. The calculation method of the microstructure dimension was reported. The turning test results show that the diamond tool can be moved up to 1kHz without any reinjected vibration in the machining and the peak-to-valley amplitude of the machined sinusoidal microstructure is about 12<${\mu}m$

• 소성∙가공
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• 제28권5호
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• pp.239-246
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• 2019

Various surface texturing techniques have been studied because of the effective applicability of micro or nano scale surface patterns. Particularly, the most promising types of patterns include the hierarchical patterns, which consists of micro/nano structures. Different processes such as MEMS, laser machining, micro cutting and micro grinding have been applied in the production of hierarchical patterns on various material surfaces. This study demonstrates the process of hot imprinting to induce the hierarchical patterns on the Al alloy surfaces. Wire electrical discharge machining (WEDM) process was used to imprint molds with micro scale sinusoidal pattern. In addition, the sinusoidal pattern with rough surface morphology was obtained as a result of the discharge craters. Consequently, the hierarchical patterns consisting of the sinusoidal pattern and the discharge craters were prepared on the imprinting mold surface. Hot imprinting process for the Al plates was conducted on the prepared mold, and the replication performance was analyzed. As a result, it was confirmed that the hierarchical patterns of the mold were effectively duplicated on the surface of Al plate.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.632-635
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• 2003

As a process technology of nano pattern with a new conception for economic and practical technology of alternative nano process. process technologies such as Embossing, Imprinting. Molding and Inking are beginning to make its appearance. Among these alternative processes, nano mold process is a process that is of benefit to mass production and keeps excellency of reproduction and high quality of parts. In this study, we experienced micro precision machining technology of nano stamper for the injection mold of optical disk with big capacity. Especially, Flatness and uniformity are important for nano stamper with global area, for the purpose of developing polishing technology of micro precision of Back polishing only being used for nano stamper, we carried out a basic study to secure flatness standards

• Tribology and Lubricants
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• 제39권5호
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• pp.216-219
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• 2023

This study employs molecular dynamics simulations to investigate the material behavior of workpieces in waterjet machining processes. To gain fundamental insights into waterjet machining, simulations were conducted using pure water, excluding abrasive particles. The simulation model comprised thousands of water molecules interacting with a single crystal metal workpiece. Water molecule clusters were imparted with various velocities to initiate collisions with the metal workpiece. The material behavior of the metal surface was analyzed with respect to the applied velocity conditions, considering the intricate interplay between water molecules and the workpiece at the atomic scale. The results demonstrated that the machining of the metal workpiece occurred only when water molecules were endowed with velocities above a certain threshold. In cases where energy was insufficient, the metal workpiece exhibited a slight increase in surface roughness due to mild plastic deformation, without undergoing substantial material removal. When machining occurred, the ejection of material revealed a 3-fold symmetric pattern, confirming that material removal in waterjet machining of the metal workpiece is primarily driven by plastic deformation-induced material ejection. This research provides crucial insights into the mechanisms underlying waterjet machining and enhances our understanding of material behavior during the process. The findings can be valuable in optimizing waterjet machining techniques.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.220-223
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• 2005

The rapid prototyping (RP) technology has been advanced for various applications such as verification of design, functional test. However, many RP machines still have low accuracy and limitation of applications for various materials. In this research, a hybrid RP system was developed to improve precision of micro parts. This hybrid system consists of deposition and material removal process by mechanical micro machining to fabricate nano composites using photo-curable polymer resin with various nano particles. In this work, using hybrid RP process with Multi-Walled Carbon Nano Tube (MWCNT) and hydroxyapatite, micro parts were fabricated. The precision of parts was evaluated based on the original CAD design, and to see the effect of nano particles on mechanical properties, tensile strength was measured. From the results of experiments, it was confirmed that the part made by hybrid process had higher precision, and the addition of nano particles improved mechanical properties.

• 한국정밀공학회지
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• 제25권3호
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• pp.7-14
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• 2008

• 한국생산제조학회지
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• 제19권1호
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• pp.94-100
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• 2010

Nowadays, several nontraditional machining(NTM) processes are widely used to machine a complex and accurate shape part of hard materials, such as titanium, ceramics, high strength temperature resistant and refractory materials which are difficult to machine and having high strength, hardness, toughness. Machining of these complex shapes in such materials by traditional machining processes are very difficult. The NTM processes is important in the areas of micro- and nano scale machining, where high accuracy and superior surface characteristics are required, which can only be achieved using these NTM processes. So, for effective selection of different NTM processes, careful decision making for a given NTM application is often necessary. An appropriate NTM process for a given material and shape condition is very difficult for the novice engineers. In this paper, an expert system based on an analytic network process(ANP) is suggested for a best selection of NTM process in a NTM application considering an prior interdependency effect among various factors.