• 한국분말재료학회지
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• 제11권5호
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• pp.412-420
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• 2004

The purpose of the present study is to determine an optimum composition using cheaper powders keeping with high performance of hard rock cutting diamond saw blade. With 50Fe-20(Cu . Sn)-30Co specimen, a part of Co was replaced by Ni(5%, 10%, and 15%, respectively). These specimens were hot pressed and sintered for predetermined time at various temperature. Sintering is performed by two different methods of temperature controlled method and specimen dimension controlled method. In order to determine the property of the sintered diamond saw blade, 3 point bending tester, X-ray diffractometer, and SEM were used. As the Co in the bond alloy was replaced by Ni, the hardness of the specimen increased. Thus the 50Fe-20(CuㆍSn)-15Co-15Ni specimen showed the maximum hardness of 104(HRB). The results of 3 point bending test showed that flexure strength decreased along with increase in Ni content. This is attributed to the formation of intermetallic compound(Ni$_{x}$Sn) determined by X-ray diffraction. The fracture surface after 3 point bending test showed that diamond was fractured in the specimen containing 0%, 5%, and 10%Ni, and the fracture occurred at the interface between diamond and matrix in the specimen containing 15%Ni. The cutting ability test showed that the abrasive property was not changed in the specimen containing 0%, 5%, and 10%Ni. The optimum composition determined in this study is 50Fe-20(CuㆍSn)-20Co-10Ni.

• 한국정밀공학회지
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• 제18권1호
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• pp.117-122
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• 2001

Many kinds of channels are used in industrial equipment and production machinery. Although mechanical saw has been used to cut many sorts of channels, there is cost rise problem because of low productivity. Shearing of channel has a special place because it helps to cut expected shape and size easily. A channel cutting die set which can be mounted and used on a hydraulic press is developed to improve the productivity of channel cutting process. Mode for the channel cutting is divided into single cut and double cut method. This study use double cut method, and the developed channel cutting die set is composed of upper and lower die set. Shearing time can be reduced from 40 minutes to 20 seconds using the developed channel cutting die set. The productivity of channel cutting process can be increased with shearing time reduction as well as cost reduction.

• Journal of Welding and Joining
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• 제21권5호
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• pp.547-554
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• 2003

Apparent mechanical properties in structural components can be different from the initially designed values due to the formation of the residual stress in metal forming and welding. Therefore, the evaluation of residual stress has great importance in the reliability diagnosis of structural components. A nondestructive instrumented indentation technique has been proposed to evaluate various strength concerning mechanical properties from the analysis of load-depth curve. In this study, quantitative residual stress estimation on API X65 welded joints for natural gas pipeline was performed by analyzing the variation of indentation loading curve by residual stress through a new proposed theoretical model. The residual stress from the indentation method was compared with that from the saw-cutting method.

• 한국도로학회:학술대회논문집
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• 한국도로학회 2009년도 추계학술대회 논문집
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• pp.493-500
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• 2009

• Journal of Biosystems Engineering
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• 제35권6호
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• pp.373-379
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• 2010

This study was carried out to develop a belt pick-up type one-row soybean cutter, using physical properties and production conditions of soybeans. The prototype soybean cutter consisted of 4 parts: cutting part, conveying part, collecting part, and travelling part. The prototype soybean cutter was designed to cut soybeans planted with a row spacing of 600 mm, and at a height of 30 mm from the bed bottom using a disk saw. Through various trials with different peripheral velocities of the disk saw and forward speed of the cutter, determined ranges of the peripheral velocity of the disk saw cutting soybeans stems were greater than 18.3 m/s. Spacing between pick-up belts (clearance) was in a range of 60~90 mm so that soybeans could be picked at heights greater than 25 cm, and the size and shape of the pick-up belt were determined the conventional manual harvesting method. The optimal ratio between the forward speed of cutter and the peripheral speed of pick-up belts were from 1 to 1.2 by theoretical analysis. the pick-up belts had a $35^{\circ}$ of tilted angle and $90^{\circ}$ of twisted angle to pick up soybeans safely from the plant input to the lower end of the belts and convey soybeans to the upper end of belts nearby a container. The soybeans at the rear container were dropped down on the soybean row with an interval. The effective field capacity of the prototype soybean cutter was 0.136 ha/h, reducing the working hour by 92% when compared with the manual cutting.

• 한국공작기계학회논문집
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• 제18권1호
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• pp.1-12
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• 2009

Presently, the semiconductor industry has the chronic problem. In the semiconductor industry, it has the semiconductor wafer, a package, the optical filter cut by using the saw blade, the mold, a laser etc. The cutting technique has the difficulty due to the rising of the production cost by the wearing of mold, the poor quality problem due to generated heat at the moment of cutting procedure and curve cutting etc. The goal of this time of national research and development project is develop the apparatus for solving the problem that the existing cutting technique has. The technology is so called waterjet abrasive method. This technology will be mainly applied to cut a semiconductor package and a wafer. Two important things to be considered are ripple effect(in other words, the scale of a market) and simplicity of an application.

• 한국산림과학회지
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• 제90권3호
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• pp.388-397
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• 2001

작업환경의 개선이 불가능한 임업에 있어서 올바른 작업자세는 불필요한 체력의 낭비 및 누적된 특정부위에서 피로로 유발되는 상해발생 예방, 체력 저하로 인한 주의력 감소로 야기되는 휴먼에러 예방 등의 직접적인 효과를 가져 올 수 있을 것으로 판단된다. 이에 본 연구는 OWAS분석기법을 이용하여 체인톱을 이용한 간벌작업, 체인톱을 이용한 피해목벌채작업, 손톱을 이용한 임내정리작업, 낫을 이용한 덩굴제거작업, 고지절단톱을 이용한 가지치기작업, 낫을 이용한 어린나무가꾸기작업에 대하여 작업자세분석을 실시하였다. 주요 작업 중, 체인톱과 낫을 이용한 작업에서 근골격계에 약간의 해를 끼침으로 가까운 시일 내에 작업자세의 교정이 필요한 수준(수준 III)의 코드비율과 근골격계에 매우 심각한 해를 끼침으로 즉각적인 작업자세의 교정을 필요로 하는 수준(수준 IV)의 코드비율이 높게 조사되었다. 체인톱을 이용한 벌목작업에서 미숙련자와 숙련자의 작업자세를 비교해 본 결과, 수준 IV의 경우 중간 수준의 숙련자가 5.1%로 14.1%의 미숙련자 보다 낮은 것으로 조사되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1995년도 제9회 학술발표회 논문개요집
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• pp.154-154
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• 1995

The Xu-Tec process is also called the double glow surface alloying technology and is a new method of surface metallurgy which can produce an alloy layers with sp ecial phisical and chemical properties on the surface of common and inexpensive mater ials. Many super alloys and alloy steels, sueh as nickel base alloys, high speed steels and staiinless steels, have been produced by Xu-Tee Process on the surfaces of carbon steels. The depth of the alloy lasyers may vary from several microns up to 300 micr ons with alloying elements in a concentration of few percentage to 100%. World wide patents for Xu-Tec process have been granted in the United states, Canada, United Ki ngdom, Australia and Japan. High performance saw blades have been successfully produced by the Xu-Tee process with much simper processing steps and less cost than bimetal high speed saw blades. A comparison of the cutting times and wear rates of the Xu-Tee blades with the conventional bimetal blades has been made. The Xu-Tee bIases demonstrates sim ilar or better performance than bimetal blades. A Xu-Tec Unit for the commercial pr oduction of Xu-Tec saw blades has been designed and manufactured. This Unit can t reat 10,000 haek saw blades at one time. Three Xu-Tec hack saw blades production I ines have been set up in China. China.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.508-511
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• 2011

Dust released from the rotating timber cutting process causes various kinds of diseases as well as safety issues. Although there were lots of efforts to reduce the amount of dust by installing large-sized dust collectors or by using expensive high-quality cutters, they proved to be not so effective. In this study we want to modify and improve the design of the rotary cutter system to prevent dust from being released to the environment as possible by using computational fluid dynamics (CFD) analysis. We have developed CFD models of the conventional cutter and several design modifications. Through the CFD analysis the characteristics of the air flow was predicted, and then the behavior of dust produced during the cutting process was analyzed for different designs. The most efficient design feature to capture dust inside the cutter as much as possible was chosen based on the CFD analysis results. Finally the prototype of the ratary saw machine was constructed and tested to check the dust capturing efficiency, which result is reasonably consistent with the predicted performance through the CFD analysis.

• 한국결정성장학회지
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• 제21권6호
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• pp.225-229
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• 2011

현재 결정질 태양전지에서 웨이퍼 가공은 대부분 슬러리 분사 방식의 다중 와이어를 이용한 방법이 사용되고 있다. 이와 같은 슬러리 분사 방식의 웨이퍼 가공은 가공속도가 낮아 생산성이 떨어지는 단점이 있을 뿐만 아니라 금속 재질의 와이어와 실리콘 블록의 직접적인 마찰에 의하여 웨이퍼 표면의 금속 불순물에 의한 오염이 발생되는 단점이 있다. 뿐만 아니라 와이어와 실리콘 블록간의 직접적인 마찰로 인하여 와이어가 빨리 마모되며, 이로 인하여 일회성의 와이어를 사용하게 되면서 제조원가는 상승하게 된다. 반면에 다이아몬드 입자가 코팅된 와이어를 이용하여 실리콘 웨이퍼를 가공하게 되면, 가공속도가 기존 슬러리 분사방식보다 빠르며, 공정진행에 따른 와이어의 마모율이 적어 와이어의 재사용에 의한 제조원가 절감이 가능하다. 따라서 이와 같은 다이아몬드 입자가 코팅된 와이어를 이용하여 가공하는 기술은 슬러리 분사방식에 비하여 더 효율적이라 할 수 있다. 본 연구에서는 슬러리 분사방식으로 가공된 웨이퍼와 다이아몬드 코팅된 와이어로 가공된 웨이퍼의 표면특성에 대하여 분석하고 셀 공정에 영향을 미치는 것에 대하여 설명하고자 한다. 또한, 다이아몬드 와이어로 가공된 웨이퍼를 활용하기 위한 셀 공정의 개선방향에 대하여 제안하고자 한다.