• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.1
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• pp.52-59
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• 2011

가계가공은 절삭 부위의 냉각작용과 윤활작용을 위해 절삭유를 많이 소모한다. 절삭유는 염소계의 극압첨가제 등이 함유되어 있어 작업자들에게 유독할 뿐만 아니라 대기의 오염을 초래하여 청정생산을 저해하게 되므로 이런 전통적인 방법은 작업자의 직업병으로부터 보호와 환경보호를 위하여 새로운 가공방법으로 변경되어야만 한다. MQL 기계가공 방법은 절삭유를 아주 소량 소모하므로 청정생산을 위한 대안으로 떠오르고 있지만 많은 작업자들이 이에 대한 기술적인 확신이 부족하여 이 방식의 사용을 주저하고 있다. 본 연구는 MQL 가공 방식에서 가공의 특성을 파악하여 표면거칠기에 영향을 미치는 인자와 범위를 찾고자 다양한 실험을 계획하고 그 결과를 분석하였다. 실험의 계획에서는 각 가공의 특성을 잘 나타낼 수 있는 인자와 수준을 선정하고, 다양한 상황의 결과를 분석하여 MQL 가공의 특성과 최적의 가공조건을 도출하였다. 본 연구의 실험 및 분석의 결과로서, 절삭 파라미터와 그의 수준이 가공특성을 잘 반영할 수 있도록 적절히 선택된다면 MQL 기계가공은 표면거칠기 향상 및 원가절감이나 환경보호 측면에서 절삭유 윤활방식을 대체하는 green manufacturing을 위한 대안이 될 수 있음을 보였다.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.2
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• pp.26-34
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• 2009

This paper is related to MQL (Minimum Quantity Lubrication) milling process, which is one of the environmentally friendly cuttings. The objective is to compare MQL milling process with conventional cutting fluid systems. To this end, machinability of MQL milling process was investigated, followed by the cost evaluation. Cutting force, surface roughness, tool wear, and cutting temperature were compared with each cutting fluid method. Consequently, total production costs wear evaluated with the mathematical models in terms of machining cost and cutting fluid loss.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.3
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• pp.74-81
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• 2009

At present, industries and researchers are looking for ways to reduce the use of lubricants because of ecological and economical reasons. Therefore, metal cutting is to move toward dry cutting or semi-dry cutting. One of the technologies is known as MQL machining. This paper presents an investigation into MQL machining with the objective of evaluating cylindricity and cooling effect for the turning process of SM45C. To reach this goal, cylindrical-outer-diameter turning experiments are carried out according to cutting conditions with fluid, MQL and dry machining methods. A cutting force, tool-shank temperature and cylindricity of workpiece are measured and analyzed. The correlation between cutting conditions and cylindricity are evaluated according to cooling lubricant environments.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1493-1498
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• 2010

This paper present the characteristics of micro- and meso-scale milling processes in which compressed cold air, minimum quantity lubrication (MQL) and $MoS_2$ nanofluid MQL are used. For process characterization, the microand meso-scale milling experiments are conducted using desktop meso-scale machine tool system and the surface roughness is measured. The experimental results show that the use of compressed chilly air and nanofluid MQL in the micro- and meso-scale milling processes is effective in improving the surface finish.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.4
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• pp.1-8
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• 2018

In drilling Inconel 601, which is used for compressor cases in aircraft engines, a lot of cutting oil must be supplied. This prevents tools from wear and fracture due to the heat buildup resulting from the high-temperature resistance and toughness of this alloy. However, the cutting oil supply has compromised the machining environment. This has caused attention to shift to an environmentally friendly cutting fluid supply system called the Minimum Quantity Lubrication(MQL) system. The aim of this study was to find a more efficient drill processing method using MQL and to verify its performance. To that end, the properties of Inconel that make it difficult -to -drill were studied by a comparison with the drilling of SM45C. Specific factors (i.e., cutting force and tool wear) were examined in relation to the conditions in the MQL-based drilling system. Based on these results, a sealed cover and step feed were proposed as measures to increase the effectiveness of the MQL system. The efficiency of the proposed method was established.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.1
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• pp.43-50
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• 2009

Semi dry cutting known as MQL (Minimum Quantity Lubrication) machining is widely spreaded into the machining shops nowadays. The objective of this research is to suggest how to derive optimum cutting conditions for the milling process in MQL machining. To reach these goals, a bunch of finish milling experiments was carried out while varying cutting speed, feed rate, oil quantity, depth of cut and so on with MQL. Then, response surface analysis was introduced for the variance analysis and the regression model with the experimental data. Finally, desirability function based on regression model was used to obtain optimal cutting parameters and verification experiment was done.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.6
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• pp.159-166
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• 2013

In order to develop the optimum shape of an MQL carbide end-mill suitable for high speed machining of wing ribs which are a detailed part of larger wing structures, using a new material Al-Li alloy, a new MQL carbide end-mill is created that has various quantities of holes, hole sizes, and hole locations. A theoretical machining graph is generated using the hammer test and FRF simulation, and a machining test is performed in order to verify the machining stability in the high speed machining area. The optimum configuration of the MQL carbide end-mill is also presented through comparing the chattering, machining noise and cutting conditions, including the maximum cutting depth, rpm, and feed rate per teeth, for each cutter.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.63-69
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• 2013

Many researchers are trying to reduce the use of lubrication fluids in metal cutting to obtain safety, environmental and economical benefits. The aim of this study is to determine the optimization lubrication conditions in minimum quantity lubrication(MQL) turning of workpieces with taper angle. This study has been considered about various conditions of MQL. The objective functions are cutting force and surface roughness. Design factors are nozzle diameter, nozzle angle, MQL supply pressure, distance between tool and nozzle and length of supply line. The cutting force and surface roughness were statistically analyzed by the use of the Box-Behnken method. As a results, optimum lubrication conditions were suggested and verification experiment has been performed. The results of this study are expected to help the selection of lubrication conditions in MQL turning.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.3
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• pp.54-61
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• 2007

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, it causes occupational diseases for workers and air pollution in environment. Because of these problems generated, developed countries do not permit the excessive usage of lubricant in machining shops. This research focuses on the development of MQL machining technique that consumes minimal amount of lubricant, which reduces possible outbreak of occupational diseases and air pollution. This research sets experimental equipments for MQL machining. Experiments for this study are designed with major machining parameters in MQL. Through the analysis of experiments, this paper presents the optimal machining parameters.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.4
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• pp.83-91
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• 2006

At present, industry and researchers are looking for ways to reduce the use of lubricants because of ecological and economical reasons. Therefore, metal cutting is to move toward dry cutting or semi-dry cutting. One of the technologies is known as MQL(Minimum Quantity Lubrication) machining. This research presents an investigation into MQL machining with the objective of deriving the optimum cutting conditions for the turning process of SM4SC. To reach these goals several finish turning experiments were carried out, varying cutting speed, feed rate, oil quantity and so on, with MQL and flood coolant. The surface roughness and cutting force results of tests were measured and the effects of cutting conditions were analyzed by the method of Analysis of Variance(ANOVA). From the experimental results and ANOVA, this research proposed optimal cutting conditions to improve the machinability in MQL turning process.