• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.585-590
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• 2002

Abrasive water-jet(AWJ) machining is a new cutting technology. The AWJ can cut various materials touch as metal, glass and stone. However, the AWJ machining makes troubles including kerf, rounding and side taper. In this study, we investigated the correlation between parameters of abrasive water-jet machining arid cutting characteristics. The machining parameter were the material thickness and the traverse speed. The experiment was conducted to cut the stainless steel(STS41) and the mild steel(SS41) specimens. The results of the experiment weirs presented as the relation between cutting conditions and trouble of a dimension error, a conner error, an uncut width and a kerf.

• Korean Journal of Computational Design and Engineering
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• v.9 no.3
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• pp.246-252
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• 2004

Presented in this Paper is a Micro Machining Service .(MIMS) based on the World Wide Web technologies. In order to ensure easy access to the service, the web browsers are used as the user interface. The pan geometry as an STL file is uploaded with process parameter for 3-axis CNC milling. Depending on the predefined user level, novice or expert, the user interface requires different parameters for process planning. An STL-based CAM resides in the server and automatically provides NC codes upon user's request. Tool-paths for scanning and pencil-cut, which are interference-free and precise, are created by the curve-based polyhedral machining method. A couple of sample parts were fabricated by a micro endmill with 127 fm diameter. From the tests, the parts fabricated by scanning followed by pencil-cut resulted in less error(within 2%) than the parts machined only by scanning tool-path.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.1
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• pp.31-36
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• 2009

Micro-machining technology has been adopted for shape accuracy of micrometer and sub-micrometer scale, surface roughness of tens nanometer in industries. In micro-machining process the quality of machined surface is derived from machining condition and tooling. This paper investigates AE(acoustic emission) and cutting force signals according to machined surface quality related to machining condition. Machined surface quality was analyzed by the AE and cutting force parameter which reflect surface morphology. The characteristics of signal were extracted for process optimization by monitoring both the tool condition and the machined surface texture in micro end milling process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.83-88
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• 2001

In order to suggest the proper optimal conditions of the CNC milling machining for the Thin-wall surface, some experiments were carried out. The process was applied in the aerospace industry for the machining of light alloys, notably aluminium. In recent year, however, the mold and die industry has begun to use the technology for the production of components, including those manufactured from hardened tool steels. And the end mill is an important tool in the milling process. A typical example for the end mill is the milling of pocket and slot in which a lot of material is removed from the workpiece. Therefore the proper selection of cutting parameter for end milling is one of the important factors affecting the cutting cost. In this paper, we choose the optimal parameters(cutting forces) to cut thin-walled Al part by experiment.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.500-503
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• 2003

The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.422-427
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• 2004

The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining and to develop a software for design of end mill geometry.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.5
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• pp.115-120
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• 1999

This research is a described result of experimental for the parameter's effecting the microhole machining by Nd-Yag laser, The parameters are energy, pulse interval time a kin of assisting gas and its pressure. The result reveals that parameter value of energy 0.08J, pulse 20Hz, interval time of 300 microseconds could be a good machining condition to make upper microhoel that is the diameter range of 50-70${\mu}{\textrm}{m}$. At tat time the assistant gas such air, $O_2$, Ar $N_2$, was appelied. Assistant gas of air makes heat affected zone enlarge due to burning of material surface. Also it makes microhole irregular and damageable. Because of refusion caused by chemical reaction with $Al_2O_3$ ceramic material . The $O_2$(99.9%) has good characteristics to get good drilling and smooth surface on pressure of 0.2kgf/$\textrm{cm}^2$ but it is expensive. Ar, $N_2$ make material crack and burnning and proved that to be unappropriate but, Ar was a better than $N_2$.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.521-526
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• 2001

This research develops a low-cost and high accurate kinematic calibration method for a parallel typed machining center tool. A planar table is used for a mechanical fixture restricting the platform to place at the constrained pose and a low-cost and high accurate digital indicator is employed for a device checking if the constrained movement is satisfied within the established range. The kinematic parameters calibrated with respect to a single plane aren't influenced from the misalignment of the plane. A parameter observability is successfully obtained even through one planar constraint, which guarantees that the kinematic parameters is estimated by minimizing the cost function.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.464-468
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• 1996

To evaluate the surface integrity of machined products such as die, the surface roughness measurement is being much used. Especially, for machining automation and promotion of productivity, the surface roughness measurement technique changes from sepatate measuring system after machining process to the on-the-machine measurement. This study is on the surface roughness measurement by using scattered lights for on-the-machine measurement. This system is designed with a simple optical construction. And experiments are implemented with standard roughness specimen to obtain the parameters which are specularly reflected region parameter and diffusely reflected region parameter. To determine the surface roughness quickly, neural network is used. And this system gives the possibility to apply to the various production processes.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.116-125
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• 1998

In this paper, main target is to select parameters for prediction of tool wear and detection of tool fracture. The research about choosing parameter for prediction of tool wear is done by using force ratios. Also current sensor, tool-dynamometer, and accelerometer are used for researching detection method of tool fracture. Experiment is done using Taguchi's method in medium machining conditions. Parameter which is best for prediction of tool wear and detection of tool fracture by deviation analysis is selected. In this paper, tool wear means flank wear.