• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.77-82
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• 2016

When drilling through Inconel 601 nickel-chromium-based alloys, a large amount of cutting oil is required to prevent tools from wear and fracturing due to heat buildup resulting from the high temperature resistance and toughness of this alloy. However, cutting oil supply has become a factor compromising the machining environment, and this has caused attention to shift to a more environmentally friendly cutting fluid supply system called minimum quantity lubrication (MQL). Our aim in this study was to find a more efficient drill processing method using MQL, and to verify its performance. To that end, we proposed a sealed cover, a step feed, and POSS-type cutting oil as measures to increase the effectiveness of MQL in view of the cutting force and tool wear, and established an improvement in efficiency using the proposed measures.

• 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 for Precision Engineering
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• v.25 no.6
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• pp.159-167
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• 2008

Cooling lubricants are used in machining operations in order to reduce friction at the tool-chip and tool-workpiece interfaces, cool both chip and tool, and remove chip. Furthermore, they influence a strong effect on the shearing mechanisms and, consequently, on the machined surface quality and tool wear. However, several researchers state that the costs related to cutting fluids is frequently higher than those related to cutting tools. Moreover, the cooling lubricants cause an increase in both worker's health and social problems related to their use and correct disposal. Therefore, many researchers have focused on the environmentally conscious machining technologies. One of the technologies is known as MQL(Minimum Quantity Lubrication) machining. In this paper, an experimental model to obtain the optimal cutting conditions in MQL turning was suggested, and the effects of cutting conditions on surface roughness and cutting force were analyzed. For these purposes, FFD (Fractional Factorial Design) and RSM (Response Surface Methods) were used for the experiment. Cutting force and surface roughness with different cutting conditions were measured through the external cylindrical turning of Al 6061 based on the experiment plan. The measured data were analyzed by regression analysis and verification experiments with random conditions were conducted to confirm the suggested experimental model.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.7-14
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• 2017

This study manufactured a minimum quantity lubrication (MQL) supply system and identified the optimal MQL machining cutting conditions for plastic mold steel (SCM440). A series of experiments were consisted of twice. Optimal cutting conditions were derived using the Taguchi method, and cutting force variance; surface roughness; tool wear; and cutting temperature in dry, wet, and MQL machining were measured experimentally for these optimal conditions. The measured results decreased from dry to wet and MQL machining, being particularly large for dry machining due to increased cutting time. Measured MQL machining metrics were similar to those for wet machining, particularly for surface roughness, which is an index of machining quality.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.371-380
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• 2010

This study was performed to develop a precise single residue analytical method of fungicide cyprodinil in representative crops for using as general residue analytical methods which could be applied to most of crops. Apple, mandarin, Korean cabbage and green pepper were selected as representative crops, and they were macerated, extracted with acetonitrile, concentrated and partitioned with n-hexane. Then the extracts were concentrated and cleaned-up through silica gel column with ethyl acetate:n-hexane (15:85, v/v) before concentration and analysis with HPLC. LOQ (limit of quantitation) of cyprodinil was 5 ng (S/N>10) and MQL (method qnantitation limit) was 0.05 mg/kg. Recoveries were measured at three fortification levels (MQL, 10MQL and 100MQL) on crop samples and ranged from 82.0 to 108.2% and coefficients of variation were less than 10% regardless of sample type.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.245-251
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• 2004

This paper is studied on the effect of TiAlN coated Ball End Mill and MQL(Minimum Quantity Lubrication) cutting condition on cutting characteristic of high hardness steels. KP4 steels[HRC32] and STD11[HRC60] heat treated steels were used as the workpiece and WC-Co ball end mill and single and multi layer TiAlN coated ball end mill were utilized in the cutting tests. MQL device was used to spray botanical oil coolant. Result showed that TiAlN coated ball end mill were increased the cutting length than WC-Co ball end mill in the cutting speed[$245{\sim}320m/min$] about $2.3{\sim}5.7$ times for KP4 steels and about $2.5{\sim}4.3$ times far STD11 heat treated steels. The multi layer TiAlN coated ball end mill is good for KP4 steels than single layer coated.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.1
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• pp.49-55
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• 2015

Recently, many researchers and industry are looking for ways to decrease the use of lubricants because of economical and environmental reasons. One of the lubrication technologies is the MQL method. This study presents a research of MQL and Wet milling processes of Al 6061 material. For this experiment, the test specimen is suggested, and various machining conditions are applied. And, shape of micro-pattern which has been recently spotlighted is included in the test specimen. In order to compare MQL with Wet machining, several milling experiments were carried out, varying feed rate, cutting speed, depth of cut, etc. Finally, the surface roughness results of machining tests according to the process conditions were measured. It is expected that the results of machining experiments can be used to predict the surface roughness of various MQL milling processes.

• Design & Manufacturing
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• v.13 no.3
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• pp.41-47
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• 2019

In conventional machining, the use of cutting fluid is essential to reduce cutting heat and to improve machining quality. However, to increase the performance of cutting fluids, various chemical components have been added. However, these chemical components during machining have a negative impact on the health of workers and cutting environment. In current machining, environment-friendly machining is conducted using MQL (minimum quantity lubrication) or cryogenic air spraying to minimize the harmful effects. In this study, the injection nozzle that can combined injecting minimum quantity lubrication(MQL) and cryogenic gas was designed and the shape optimization was performed by using computational fluid dynamics(CFD) and design of experiment(DOE). Performance verification was performed for the designed nozzle. The diameter of the sprayed fluid at a distance of 30 mm from the nozzle was analyzed to be 21 mm. It was also analyzed to lower the aerosol temperature to about 260~270K.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.5
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• pp.671-682
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• 1995

In this paper, we propose a multimedia query language MQL which defines and manipulates multimedia data as integration of monomedia data in time and space. The MQL is designed for a multimedia data model, called the object-relationship model, and based on the multimedia object calculus which formally describes operations on multimedia data. The SQL- like syntax for class definition and object manipulation, such as retrieval, insert, update, and delete, is defined. We show how the MQL can represent the user queries using composite temporal-spatial class structures and various relationships, such as equivalence and sequence.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.309-310
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• 2002

A minimal quantity lubrication (MQL) machining is able to achieve both functions of cooling and lubrication with an extremely low quantity of a cutting fluid and a large amount of air blow. Using a biodegradable ester oil, turning tests were carried out to evaluate the effectiveness of the MQL system. It was found that the performance of MQL cutting was equivalent to, or better than, that of conventional cutting, because the MQL system tends to prevent the heat damage of the tool tip and, if an effective lubricant such as a particular polyol ester is applied to the system, it can avoid the extensive transfer of workpiece materials on to the tool surface.