• Journal of the korean Society of Automotive Engineers
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• v.11 no.5
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• pp.34-45
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• 1989

성장하는 균열에 의한 변형 에너지해방에 기반을 둔 간단한 파괴역학적인 접근법이 고무의 여러가지 특성을 규명하는데 성공적으로 응용되는 예들을 논의하였다. 이 방법은 전통적인 강도, 즉 찢김, 균열성장, 피로, 인장파손 등 뿐만 아니라 오존내습(ozone attack), 예리한 공구들에 의한 마쇄, 절단현상을 규명하는데도 응용가능함을 밝혔다. 특히 에너지해방율은 여러가지의 다른 시험편에 대한 실험값들이 서로 연관성을 갖도록 허용하기 때문에 매우 유용한 특성이라 할 수 있다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.05a
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• pp.135-140
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• 2003

산업이 고도화됨에 따라 각종 기계·기구에 사용되는 부품의 고정도가 요구되면서 기존에 공구와 가공물이 직접 접촉하면서 절삭하는 가공방법으로는 절삭력에 의한 변형과 마찰열로 인하여 고정도 가공을 실현하는데 많은 어려움이 생기게 되었다 이러한 절삭가공법 중 연삭가공은 주로 가공물의 마무리에 이용되는 가공법으로서, 비교적 정밀하고 양호한 표면의 품위가 요구되어지는 부품에 사용되어왔다.(중략)

• Design & Manufacturing
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• v.17 no.4
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• pp.24-32
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• 2023

In this study, we introduce research aimed at minimizing machining errors without compromising productivity by compensating for the machining errors caused by tool deformation. Our approach experimentally establishes the direct correlation between cutting depth and machining error, and creates predictive models using mathematical functions. This method allows for the prediction of compensated cutting depths to obtain the desired cutting profiles, thereby maximizing the compensation of machining errors in the cutting process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.2073-2080
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• 1997

Recently, the plane strain puch stretching test(called PSST) has been developed and used successfully in the evaluation of the press formability of automotive steel sheets. In this paper, the optimum punch geometry of the original PSST tool was investigated by the FEM analysis. The puch length, crown and corner radius are chosen to be optimized according to the Taguchi's experiment technique with the $L_4$ orthogonal array.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.204-209
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• 2004

Using STD11 and STS3 as a mold set, accuracy of a mold product could be improved by heat treatment. Results of Charpy impact test and measurement of retained austenite in STS3 and STD11, STD11 was superior than STS3 in effect of sub-zero treatment and stability of working and measure. Decrease of retain austenite by sub-zero treatment in STS3 did not occured.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.3
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• pp.75-81
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• 1998

In the machining process, variation in cutting forces results in relative displacements between the tool and the workpiece leading to tool vibration. Also there is a demand to change the depth of cut very frequently. One solution for the both cases is to develop a system which has the ability to reposition a cutting tool to a very small level, i.e., micron. This paper presents the development of a micropositioner using a magnetostrictive material. The developed micropositioner is implemented to a lathe and subjected to various tests. The results show that the micropositioner with a magnetostrictive actuator has good potential for machining application.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.302-307
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• 2002

In end milling process, the undeformed chip section area and cutting forces vary periodically with phase change of the tool. However, the real undeformed chip section area deviates from the geometrically ideal one owing to cutter runout and tool shape error. In this study, a method of estimating the real undeformed chip section area which reflects cutter runout and tool shape error was presented during up-end milling of Inconel 718 using measured cutting forces. The specific cutting resistance, K. and $K_t$ are defined as the radial and tangential cutting forces divided by the modified chip section area. Both of $K_r$, and $K_t$ values become smaller as the helix angle increases from $30^\circ$ to $40^\circ$ Whereas they become larder as the helix angle increases from $40^\circ$ to $50^\circ$. On the other hand, the $K_r$, and $K_t$ values show a tendency to decrease with increase of the modified chip section area and this tendency becomes distinct with smaller helix angle.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.308-313
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• 2002

In end milling process, the undeformed chip section area and cutting forces vary periodically with phase change of the tool. However, the real undeformed chip section area deviates from the geometrically ideal one owing to cutter runout and tool shape error. In this study, a method of estimating the real undeformed chip section area which reflects cutter runout and tool shape error was presented during down end-milling of Inconel 715 using measure cutting forces. Contrary to the up-end milling the value of radial specific cutting resistance, $K_r$, becomes larger as the helix angle increases from $30^{\circ}$ to $40^{\circ}$ and it shows almost same value at $50^{\circ}$ The value of tangential specific cutting resistance, $K_t$ becomes larger as the helix angle increases same as in up-end milling, the $KK_r$, and $K_t$ values show a tendency to decrease with increase of the modified chip section area and this tendency is distinct with helix angle $40^{\circ}$.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.63-70
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• 2002

In end milling process, the undeformed chip section area and cutting forces vary periodically with phase change of the tool. However the real undeformed chip section area deviates from the geometrically ideal one owing to cutter runout and tool shape error. In this study, a method of estimating the real undeformed chip section area which reflects cutter runout and tool shape error was presented in up end milling process using measured cutting forces. The average specific cutting resistance, Ka is defined as the main cutting force component divided by the modified chip section area. Ka value becomes smaller as the helix angle increases from $30^circC \;to\;40\circC$. But it becomes larger as the helix angle increases from $40^\circ$to 50 . On one hand, the Ka value shows a tendency to decrease with increase of the modified chip section area and this tendency becomes distinct with smaller helix angle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.1
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• pp.15-21
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• 2004

The machining process of ceramics can be characterized by cracking and brittle fracture. In the machining of ceramics, edge chipping and crack propagation are the principal reasons to cause surface integrity deterioration. Such phenomenon can cause not only poor dimensional and geometric accuracy, but also possible failure of the ceramic parts. Thus, traditional ceramics are very difficult-to-cut materials. To overcome such problems, in this paper, h-BN powder, which gives good cutting property, is added for the fabrication of machinable ceramics by volume of 5, 10, 15, 20, 25 and 30%. The objectives of this paper is to evaluate the fracture phenomenon of the tungsten carbide tool and the variation of surface integrity of the manufactured machinable ceramics under various cutting conditions during end mill machining With CNC machining center.