• 한국정밀공학회지
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• 제19권8호
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• pp.55-62
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• 2002

A burr has been defined as undesirable projection of material formed as the result of plastic flow from a cutting or shearing operation. It is unavoidable in all kinds of machining operation. As a result, burr makes troubles on manufacturing process due to deburring cost, quality of products and productivity. In face milling operation, burrs are formed along five edges on the workpiece. In this study, the primary interest is about exit burr The influence of the cutting parameters on the formation of exit burrs in face milling will be described experimentally. Using the results of experimental study, burr types are classified according to appearance and formation mechanism in exit burr. The burr formation mechanism in each type of burr is suggested. Data bases are developed to predict burr formation result.

• 한국기계가공학회지
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• 제11권3호
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• pp.24-28
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• 2012

In this paper, the high speed milling characteristics of Al6061 was studied. A gantry type milling & tapping center was developed for this study. The cutting force and the resulting surface roughness were measured at various cutting conditions. The experimental results indicate that the surface roughness is relative to the cutting conditions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1203-1206
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• 2003

After the micro turning lathe was developed in the last year by AMR Laboratory, a micro-milling machine is developed for micro machining. This machine is integrated with PZT-driven micro-sliders, micro-linear encoders, air turbine spindle which has maximum 150.000 rpm. It is applicable to milling and drilling machining. This paper shows the possibility of micro machining and characteristics of micro end milling process by using micro machine. A machining of micro barrier ribs using 0.2 mm flat type end mill was achieved by micro-milling machine. As experimental results show the machining capability and positional accuracy of this machine is good enough for machining micro parts.

• 한국기계가공학회지
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• 제19권4호
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• pp.9-15
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• 2020

Carbon fiber reinforced plastic (CFRP) is a composite material useful in the aerospace and automotive industries because of its light weight and high strength. In this study, side milling tests were carried out using AlCrN, diamond-like carbon (DLC), and diamond-coated end mills. Additionally, a comparison study according to the cobalt content was conducted. Thus, tool wear and surface quality were examined and the influences of using coating and a certain material type were analyzed. The surface roughness of the machined surface was measured. Microscope observations revealed that the CFRP fiber at the machined surface was not damaged even at a cutting distance of 3,000 mm. Therefore, this study showed that the diamond-coated end mill containing 6% cobalt is appropriate for milling CFRP.

• Advances in materials Research
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• 제7권2호
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• pp.137-148
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• 2018

The present paper is a contribution in characterising end milling process of AISI 52100 ball bearing steel through statistical analyses of variance (ANOVA). The latter has been performed to identify the effect of the cutting parameters on the machined surface roughness and the cutting tool life. Wear measurements have been carried on multilayer coated carbide inserts and the respective surface roughness has been recorded. Taguchi's technique has been adapted to conduct the design experiments in terms of orthogonal arrays according to the cutting parameters (cutting speed, feed rate and depth of cut), the type of coating (TiN, TiCN, TiAlN) and lubricating condition. Regression analyses have conducted to the development of simplified empirical models that can be effectively used to predict surface roughness and tool wear in the present milling process.

• 한국염색가공학회지
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• 제5권2호
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• pp.134-138
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• 1993

Wool, silk and nylon 6 fabrics were treated with low-temperature plasma under atmospheric pressure of acetone/argon or helium/argon for 30 and 180 sec, and then dyed with leveling type acid dye, C.I. Acid Red 18 and milling type acid dye, C.I. Acid Blue 83. In spite of short time of the plasma treatment for thirty seconds, the color depth of wool fabrics was increased remarkably with both of the plasma gases, aceton/argon or helium/argon and with the kinds of dyes i.e., levelin type or milling type. But the atmosperic low-temperature plasmas did not increase the depth of silk and nylon 6 fabrics dyed with both of the acid dyes regardless of the teated time and plasma gases. It seems that low-temperature plasma by atmospheric-pressure discharge is effective for improvement of dyeing of wools as is the same way with the low-temperature plasma by glow discharge. The kinds of plasma gases and treated time did not influnce the depth of wool fabric pretreted with the atmosperic low-temperature plasmas.

• 한국분말재료학회지
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• 제9권5호
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• pp.359-364
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• 2002

We report the structure, thermal and magnetic properties of a non-equilibrium $Al_{0.6}(Fe_{50}Cu_{50})_{0.4}$ alloy powder produced by rod milling and chemical leaching. An X-ray diffractometry(XRD), a transmission electron microscope(TEM), a differential scanning calorimeter(DSC), a vibrating sample magnetometer(VSM), and superconducting quantum interference device(SQUID) were utilized to characterize the as-milled and leaching specimens. The crystallite size reached a value of about 8.82 nm. In the DSC experiment, the peak temperatures and crystallization temperatures decreased with increasing milling time. The activation energy of crystallization is 200.5 kJ/mole for as-milled alloy powder. The intensities of the XRD peaks of as-milled powders associated with the bcc type $Al_{0.5}Fe_{0.5}$ structure formative at $350^{\circ}C$ sharply increase with increasing annealing temperature. Above $400^{\circ}C$, peaks alloted to $Al_{0.5}Fe_{0.5}$ and $Al_{5}Fe_{2}$ are observed. After annealing at $600^{\circ}C$ for 1h, the leached Ll specimen transformed into bcc $\alpha$-Fe and fcc Cu phases, accompanied by a change in the structural and magnetic properties. The saturation magnetization decreased with increasing milling time, and a value of about 8.42 emu/g was reached at 500 h of milling. The coercivity reached a maximum value of about 142.7 Oe after 500 h of milling. The magnetization of leached specimens as function of fields were higher at 5 K, and increased more sharply at 5 K than at 100 K.

• 한국식품저장유통학회지
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• 제12권3호
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• pp.230-234
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• 2005

백설기 제조시 쌀가루 제분방법 및 입자크기가 백설기 관능특성과 품질특성에 미치는 영향을 조사하였다. 품질특성 측정결과 수분함량은 제분방법에 따라 $31.9{\sim}34.8\%$로 나타났다. L value는 W80(more than $180\;{\mu}m$ rice flour using wet milling)이 가장 높은 값인 92.5를 나타냈고, D80(more than $180\;{\mu}m$ rice flour using dry milling)이 가장 낮은 값인 79.0을 나타냈다. 호화도 측정결과 제분방법에 따른 유의적인 차이가 나타나지 않았다. 조직감 측정결과 탄력성(springiness), 응집성(cohesiveness), 씹힘성(chewiness), 껌성(gumminess)은 입자크기에 따른 유의적인 차이를 나타내지 않았고, 경도(hardness) 측정결과 입자크기가 작아질수록 낮은 수치를 나타내었다. 관능검사 측정결과에서는 W80으로 만든 백설기가 강도 및 기호도 검사에서 가장 높은 점수를 나타내었다.

• Journal of Biosystems Engineering
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• 제3권1호
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• pp.33-46
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• 1978

To get the goal of self-supply of food grain, improvement of post-harvest grain operations in rural area is under consideration as an important task of agriculture in Korea. This is study is focused on elimination of losses and deteriorations of grain and reduction of labour requirements and funds for post-harvest grain operations. The purpose of this study are presentation of basic data referring to conventional post-harvest grain operations in rural area and suggestion of improving methods for the operations, and also finding out reasonable operating processes of the operations. The result of this study are follows; 1. Grain drying in-the-filed which is performed before threshing has major factors of grain loss during drying, and so should be restrained as possible. Combine harvesting system is recommended among other king of mechanized harvesting systems for restraining in-the-field drying and securing available labors for drying. 2. It is predicted that mechanical grain drying could be prevalent when combine harvesting is taken place. Recommended grain drier for pre-combine harvesting system and for combine harvesting system is batch-type drier and circulating -type drier, respectively. 3. As existing farm storages for grain have insufficient spaces and offer poor conditions for grain storing , it is greatly needed to build up new storage which store only grains. And it is concluded that storing grain in community common storages in desirable. 4. Power supplying system for milling machinery in local milling plants, that a large capacity prime mover supplies power to 4 to 6 kinds of milling machinery simultaeously, should be converted to a system of several small capacity prime movers supplying power to each machiner y for the purpose of reducing extra consumption of energy. 5. Governmental grain, of which Korean farms produced, should be milled and stored in the local milling plant successively for the purpose of reducing transportation fee and stroing facilities. 6. Furture post-havest grain operations-drying, storing and milling should be periormed successively in he community common plant. And average optimum processing capacity of the plant is estimated about 300 metric ton of grain every year.

• 한국잠사곤충학회지
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• 제34권2호
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• pp.52-57
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• 1992

견의 저온염색용 조제(K-1)를 사용하여 염료 농도, 염욕의 pH, 염색시간에 따른 염색속도를 구하여 이 저온염색용가 염색에 미치는 영향을 분석한 결과를 다음과 같이 요약한다. 1. pH 7에서 K-1의 농도가 증가할수록 무첨가구에 비해 흡진율은 증가 하였으며, K-1의 농도가 3% o.w.f. 이상에서는 증가의 경향이 둔화되었다. 2. pH 5에서도 무첨가보다 K-1의 첨가구에서 높은 흡진율을 보였으며, pH 7의 5$0^{\circ}C$ 첨가구가 pH 5, 5$0^{\circ}C$의 무첨가구보다 확산성은 높게 나타났다. 3. 염료 농도별로 볼 때 pH 7과 pH 5에서 모두 K-l 첨가구에서는 무첨가구보다 흡진율이 클 뿐만 아니라 염료 농도에 따른 흡진율 감소가 적게 일어났다.