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        검색결과 19

        2.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Injection molding is a process of shaping resin materials by heating them to a temperature above their melting point and then using a mold. The resin material is injected into and cooled within the mold cavity, solidifying into the desired shape. The core and cavity components that make up the mold cavity are crucial elements for the precision molding in injection molding. In the case of precision mold production, the application of 5-axis machining technology is required to ensure high machining quality for complex shapes, and among these factors, the tool angle is a critical machining condition that determines the surface roughness of the workpiece. In this study, we aim to measure the surface roughness of the machined surface of KP4A specimens during machining processes with variations in the tool angle and analyze the correlation between the tool angle and surface roughness.
        4,000원
        3.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, halogen lamps for vehicle exterior lamp systems are being replaced by LEDs (Light Emitting Diode) in consideration of miniaturization, power consumption, life, luminance, and eco-friendliness. Due to regulations on the amount of light required, luminance, light uniformity, and glare prevention, it is required to develop a light guide for controlling a light source of an LED lamp for a vehicle. For the development of the light guides, the development of machining technology that can cut micro patterns of hundreds of micrometers scale into surface roughness of tens of nanometers scale must be preceded. In this study, the effect of variations in cutting conditions on surface roughness was analyzed through experiments. The micro patterns was manufactured by cutting into STAVAX material, and the surface of the micro patterns was super-finished using a ball-shaped PCD (polycrystalline diamond) tool without flutes. In experiments, the cutting conditions of the super-finishing process were varied, and the varied cutting conditions were feed rate, radial depth of cut, and spindle speed
        4,000원
        4.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The function of coolant in machining is to reduce the frictional force in the contact area in between the tool and the material, and to increase the precision by cooling the work-piece and the tool, to make the machining surface uniform, and to extend the tool life. However, cutting oil is harmful to the human body because it uses chlorine-based extreme pressure additives to cause environmental pollutants. In this study, the effect of cutting temperature and surface roughness of titanium alloy for medical purpose (Ti-6Al-7Nb) in eco-friendly ADL slot shape machining was investigated using the response surface analysis method. As the design of the experiment, three levels of cutting speed, feed rate, and depth of cut were designed and the experiment was conducted using the central composite planning method. The regression expressions of cutting temperature and surface roughness were respectively obtained as quadratic functions to obtain the minimum value and optimal cutting conditions. The values from this formula and the experimental values were compared. As a result, this study makes and establishes the basis to prevent environmental pollution caused by the use of coolant and to replace it with ADL (Aerosol Dry Lubricant) machining that uses a very small amount of vegetable oil with high pressure.
        4,000원
        6.
        2022.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon fiber and its composites are increasingly used in many fields including defence, military, and allied industries. Also, surface quality is given due importance, as mating parts are used in machineries for their functioning. In this work, the turning process is considered for Carbon Fiber Reinforced Polymer (CFRP) composites by varying three important cutting variables: cutting speed, feed, and depth of cut. Correspondingly, the surface roughness is measured after the completion of turning operation. As well, a prediction model is created using different fuzzy logic membership function and Levenberg–Marquardt algorithm (LMA) in artificial intelligence. Later, the surface roughness values from the developed models are compared against the experimental values for its correlation and effectiveness in using different membership functions of fuzzy logic and ANN. Thus, the experimental results are analyzed using the effect graphs and it is presented in detail.
        4,500원
        8.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A magnetic abrasive finishing process was proposed for improving the surface accuracy of microscale -diameter STS 304 bar used in many applications such as, medical, aerospace, and nuclear industries. Most of the previous research has already explored the conventional finishing technique to improve the accuracy of material in terms of the surface roughness. However, their results are still not good enough for the requirement in the today’s engineering industry. Especially, when the workpiece is a material of microscale-diameter, use of such conventional processes becomes impossible because they entail the application of high pressures that may damage the surface to be finished. Moreover, less control is available over these conventional finishing processes. In this study, an ultra-high-precision magnetic abrasive finishing process was applied to the precision machining of microscale-diameter STS 304 bar and the experimental work are performed with many critical parameters such as, different workpiece revolution speeds, abrasive grain sizes, different finishing temperatures, and pole vibrations. The results showed that in The initial surface roughness of 0.20 μm (Ra) was decreased to 0.025 μm with 0.5 μm of abrasive grain size and pole vibration 12Hz at 40,000 rpm.
        4,000원
        9.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        CNC cutting process has been mainly used for processing metal materials, and wood processing is also changing to machining by CNC machine. But the researches on the CNC machining of wood and its characteristics were rarely carried out. In this study, we analyzed the machined surface according to the cutting conditions such as the cutting direction, spindle speed, feed rate, cutting depth, chip removal in the CNC machining of wood. The consideration of cutting conditions and their effects on the surface finish will provide possibilities for improving the wood machining processes.
        4,000원
        10.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ti alloys are extensively used in high-technology application because of their strength, oxidation resistance at high temperature. However, Ti alloys tend to be classified very difficult to cut material. In this paper, The powder synthesis, spark plasma sintering (SPS), bulk material properties such as electrical conductivity and thermal conductivity are systematically examined on Ti2AlN and Ti2AlC materials having most light-weight and oxidation resistance among the MAX phases. The bulk samples mainly consisted of Ti2AlN and Ti2AlC materials with density close to theoretical value were synthesized by a SPS method. Machining characteristics such as machining time, surface quality are analyzed with measurement of voltage and current waveform according to machining condition of micro-electrical discharge machining with micro-channel shape.
        4,000원
        11.
        2013.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        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 experi- ments, 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.
        4,000원
        12.
        2009.05 구독 인증기관 무료, 개인회원 유료
        인체의 특성을 고려한 맞춤형 자유 곡면은 현대생활의 많은 부분에서 필요하지만 그 개발은 복잡하여 수리적으로 단순한 모델링을 하기가 어렵다. CAD를 이용하여 모델링을 하기도 하지만 이런 경우 특성점을 입력하여야 하는데 자유 곡면에서는 특성점을 찾기가 어렵기 때문에 역공학을 이용하여 모델링한다. 본 논문에서는 자유 곡면으로서 인체의 특성에 잘 맞는 개인 맞춤형 곡면을 모델링하여 이를 공작기계에서 가공하는 방법에 대하여 연구한다. 자전거의 안장은 자유 곡면으로서 개인의 신체특성에 맞도록 설계하며 역공학의 방법을 이용하여 모델링한다. CAD를 이용하여 수정하고 이를 가공하기 위한 공구경로를 생성한다. 가공경로를 그래픽 시뮬레이션으로 검증 하고 이를 3축 공작기계에서 생산하여 안장곡면 생산을 위한 금형개발의 기초로 하는 것이 본 연구의 주요 내용이다.
        4,000원
        13.
        2008.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
          Surface roughness is an important factor to evaluate machined parts in precision machining. This is the major measure of surface quality. This research sets up experiments to select the factors which affect surface roughness in the machining of inclined
        4,000원
        14.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
          Machining processes produce high accurate metallic parts in metal working industries. Lubrication for machining enhances quality of machined surface and it prolongs the life of cutting tools. Since lubricant is poisonous to human body and environment, i
        4,000원
        15.
        2006.09 구독 인증기관·개인회원 무료
        Aluminum-based composites reinforced with various amounts of were produced by powder metallurgy (P/M). The machinability properties of were determined by means of cutting forces and surface roughness. Machining tests were carried out by using PCD and K10 tools. Increasing of volume fraction in the matrix resulted in a decrease of the surface roughness and turning forces. PCD cutting tools showed better cutting performance than K10 tools.
        16.
        2004.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High speed machining is a machining process which cuts materials with the fast movement and rotation of a spindle in a machine tool. It reduces machining time because of the high feed and the high speed of a spindle. In addition it gets rid of post proces
        4,000원
        17.
        2003.10 구독 인증기관 무료, 개인회원 유료
        최근 고속가공에 있어서 고속가공 기술의 도입으로 금형소재의 고정밀 및 고능률가공에 대한 요구가 급증하고 있다. 가공정밀도의 개선은 제품의 부가가치를 높여주고, 생산성의 개선은 가공경비를 감소시켜 가격 경쟁력을 높여 준다. 그러나 기존의 일반절삭에 의해서는 각종 공구 및 공작물의 재질에 따른 절삭조건의 제한으로 이러한 요구에 부응하지 못하고 있다. 이러한 관점에서 고속가공은 황․정삭 가공 개념 없이 생산성 향상과 밀접한 관계가 있으며 가공 능률 향상과 공정감소로 인한 경비절감을 꾀할 수 있어 최근 이에 대한 연구가 활발히 이루어지고 있다. 본 연구에서는 이러한 고속가공에 있어서 그 표면거칠기를 모델링하여 최적화하고자 한다. 고속가공에서 주축회전수, 이송속도를 변화시켜가며 가공 실험하여 얻은 표면거칠기 데이터를 바탕으로 bicubic polynomial 곡면보간법으로 주축회전수와 이송속도에 따른 표면거칠기 곡면 근사식을 유도한다. 즉 이 근사식을 이용하여 표면거칠기의 최적해를 구하고자 한다.
        3,000원
        18.
        2003.05 구독 인증기관 무료, 개인회원 유료
        최근 산업의 급속한 발전과 더불어 각종 기계 구성 부품의 고정밀 및 고능률 가공에 대한 요구가 급증하고 있는 실정이나 기존의 일반절삭에 의해서는 각종 공구 및 공작물의 재질에 따른 절삭조건의 제한으로 이러한 요구에 부응하지 못하고 있다. 이러한 관점에서 고속가공은 황․정삭 가공 개념 없이 생산성 향상과 밀접한 관계가 있으며 가공 능률 향상과 공정감소로 인한 경비절감을 꾀할 수 있어 최근 이에 대한 연구가 활발히 이루어지고 있다. 본 연구에서는 이러한 고속가공에 있어서 표면거칠기의 최적화 방법을 유전알고리즘을 이용하여 제안하고자 한다. 고속가공에서 주축회전수, 이송속도를 변화시켜가며 가공 실험하여 얻은 표면거칠기 데이터를 바탕으로 bicubic polynomial 곡면보간법으로 주축회전수와 이송속도에 따른 표면거칠기 곡면 근사식을 유도한다. 이 근사식을 목적함수로 하여 유전알고리즘을 적용하여 표면거칠기의 최적해를 구하고자 한다.
        4,000원