• 한국산학기술학회논문지
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• 제14권9호
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• pp.4149-4155
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• 2013

더 빠른 절삭속도와 이송속도를 위한 고속가공은 표면품위와 재료제거율의 증가를 초래한다. 이 논문은 고속가공을 위한 정면밀링커터를 사용한 가공에서 획득된 진동특성에 관한 절삭조건의 영향을 연구하였다. 이 논문에서, 직교배열 테이블에 기초한 다구찌 실험계획법은 고속 정면밀링커터를 사용한 진동특성을 연구하기 위해 적용되었다. 실험조건은 직교배열 $L_{27}(3^{13})$ 을 사용하였다. 실험의 계획과 분석은 S/N비(신호 대 잡음비)와 분산분석을 이용하여 진동에 관한 절삭조건의 영향을 연구하기 위해 수행되었다. 절삭 파라미터 즉 이송속도, 챔퍼길이, 절삭속도 그리고 절삭깊이는 진동 특성치를 고려하여 최적화 되었다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.155-160
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• 2001

In the use of glass fiber reinforced plastics(GFRP) it is often necessary to cut the components, but the cutting of GFRP is often made difficult by the delamination of the compositions and short tool life. Experimental investigation was conducted to evaluate the chip formation of the glass fiber reinforced plastics during orthogonal cutting. The chip formation process, cutting force, and thrust force were studied. The chip formation processes were studied through the use of quick-stop device. Chip-tool contact areas were obtained with the use of the quick-stop device, and observed using optical microscopy after polishing. Cutting force and thrust force were measured through the use of the tool dynamometer.

• 한국기계가공학회지
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• 제8권4호
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• pp.48-53
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• 2009

Inconel 718 alloy, widely used as material of aircraft engine, has a good mechanical property in high temperature, strong anti-oxidation characteristics in oxidated current over $900^{\circ}C$, and also is not easily digested in the air containing sulfur, therefore, its usage as mechanical component is expanding rapidly. Even though Inconel alloy 718 is difficult to machine, it requires highly precise processing/machining to sustain its component quality of high accuracy. In this paper, general turning operation conditions are tested to select the best cutting process condition by measuring surface roughness through implementing experiments with orthogonal array of cutting speed, feeding speed and cutting depth as processing parameters based on the Taguchi method. Optimal turning operation conditions are extracted from the proposed experimental models.

• 대한기계학회논문집A
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• 제39권1호
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• pp.95-103
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• 2015

평엔드밀 가공된 측벽 형상에 공구 형상이 미치는 영향에 대하여 알아보고자 한다. 이를 위하여, 공구 형상을 비틀림각, 절삭날 수, 직경으로 구분하여 특징지었으며, 가공면의 기하학적 특성은 서로 직교하는 이송방향 형상과 축방향 형상으로 나누어 고려하였다. 각 방향의 형상 특성은 공구와 공작물 및 절삭날과 공작물의 간섭 영역으로부터 계산한 순간 절삭면적을 바탕으로 추정하였으며, 추정의 타당성을 가공면 형상 및 배분력 측정을 통하여 검증하였다. 연구 결과, 이송방향 형상의 결함은 공구 퇴출 및 공구 경로의 곡률반경이 변하는 구간에서 나타나며, 이외의 구간에서는 축방향 형상의 결함이 주를 이루는 것이 확인되었다. 측벽의 가공정밀도를 향상시키기 위해서는, 상대적으로 직경이 작고, 비틀림각이 큰 절삭날을 많이 갖는 엔드밀을 사용하여 상향절삭 하는 것이 바람직할 것으로 추천된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.1012-1015
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• 2001

The purpose of this paper is to evaluate the specific cutting energy characteristics during turning SM45C steel. Using the orthogonal array method the specific cutting energy has been predicted. And the significance of the equation is checked by ANOVA test. Predicted values of specific cutting energy are well concide with the measured ones. When the feed rate becaomes larger than 0.5mm/rev, predicted specific cutting energy increases.

• 한국기계가공학회지
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• 제11권4호
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• pp.31-38
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• 2012

In this paper, we selected primary cutting parameters that influence on surface roughness of cut bottom surface in end-milling for SM25C material. Those are overhang, depth of cut, feed rate and spindle speed. And then performed orthogonal array experiment and ANOVA by Taguchi method to determine that improved level combination of cutting parameters for betterment of working efficiency and surface roughness one of quality characteristics. And we verified a advisability of prediction model by verification test about level combination. From the results, main cutting parameter influences on surface roughness is spindle speed and the next is feed rate.

• 한국기계가공학회지
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• 제17권6호
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• pp.68-74
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• 2018

Study on the Ti-6Al-4V have been carried out using cutting simulation, and researches for cutting force and chip shape prediction have been actively conducted under various conditions. However, a 3D printer application method using Ti-6Al-4V metal powder material as a high-power method has been studied for the purpose of prototyping, mold modification and product modification while lowering material removal rate. However, in the case of products / parts made of 3D printers using powder materials, problems may occur in the contact surface during tolerance management and assembly due to the degradation of the surface quality. As a result, even if a 3D printer is applied, post-processing through cutting is essential for surface quality improvement and tolerance management. In the cutting simulation, the cutting force and the chip shape were predicted based on the Johnson-Cook composition equation, but the shape of the shear type chip was not predictable. To solve this problem, we added a damaging term or strain softening term to the Johnson-Cook constitutive equation to predict chip shape. In this thesis, we applied the constant value of the S-K equations to the cutting simulation to predict the cutting force and compare with the experimental data to verify the validity of the cutting simulation and analyzed the machining characterization by considering conditions.

• 한국정밀공학회지
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• 제33권6호
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• pp.439-445
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• 2016

Carbon fiber reinforced plastic (CFRP) composites have been widely used due to their great strength, stiffness and light weight. However, due to its anisotropy and inhomogeneous properties the machining process of CFRP composites is typically more complex than that of regular metals. Since there are many defects, such as delamination and tool wear during the machining process of CFRP composites, the optimization of this process is essential in improving the productivity. In this study, orthogonal machining of CFRP composites was performed to identify the machining characteristics of these materials. In addition, an experimental observation of delamination was investigated through the use of scanning electron microscopy (SEM). In these experiments, the cutting forces were measured and analyzed to determine the difference between machining of CFRP composites and metals. The comparison between the numerical models and experimental results was performed in terms of the maximum cutting forces.

• 한국생산제조학회지
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• 제19권2호
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• pp.295-300
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• 2010

Inconel 718 alloy, widely used as material of aircraft engine, has a good mechanical property in high temperature, strong anti-oxidation characteristics in oxidated current over $900^{\circ}C$, and also is not easily digested in the air containing sulfur, therefore, its usage as mechanical component is expanding rapidly. Even though Inconel alloy 718 is difficult to machine, it requires highly precise processing/machining to sustain its component quality of high accuracy. In this paper, general turning operation conditions arc tested to select the best cutting process condition by measuring surface roughness through implementing experiments with orthogonal array of cutting speed, feeding speed and cutting depth as processing parameters based on the Taguchi method. Optimal turning operation conditions are extracted from the proposed experimental models.

• 한국기계가공학회지
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• 제5권4호
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• pp.59-64
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• 2006

High Speed Machining(HSM) reduces machining time and improves surface accuracy because of the high cutting speed and feedrate. Development of HSM makes it allowable to machine difficult-to-cut material and use small-size-endmill. It is however limited to cutting condition and tool material. In the machining operation, it is important to check main parameter of tool life and select optimal cutting condition because tool breakage can interrupt progression of operation. In this study, cutting parameters are determined to 3 factors and 3 levels which are a spindle speed, a feedrate and a width of cut. Experiment is designed to orthogonal array table for L9 with 3 outer array using Taguchi method. Also, it is proposed to inspect significance of the optimal factors and levels by ANOVA using average of SN ratio for tool life. Finally, estimated value of SN ratio in the optimal cutting condition is compared with measured one in the floor shop and reduction of loss is predicted.