• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.1
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• pp.131-137
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• 1986

Cutting oil cools the chip and a tool as well as lubricates the chip-tool interface, the flank and machined surface. Rehbinder effect has been known as a phenomenon, the reduction of mechanical strength, when the metal is exposed to a polar organic environment or the surface of metal is coated with some polar organic substances. About the cause of Rehbinder effect there have been many different ideas by Rehbinder, Shaw, Barlow, Sakida and etc. In this report, the efect of polar organic substance( $C_{6}$ $H_{5}$C $H_{3}$+ $C_{6}$ $H_{4}$(C $H_{3}$)$_{2}$+ $C_{4}$ $H_{9}$OH+ $C_{6}$ $H_{12}$ $O_{2}$) (magic ink) upon the mechanism of chip formation on the orthogonal cutting of copper and mechanical properties of the work material are experimentally discussed with various rake angles. As expected no lubrication action could be noticed, but the shear angle increased and the cutting force and shear strain on the shear plane decreased, therefore the work material must be embrittled under polar organic substance.substance.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.1951-1962
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• 1993

The creation process of a typical machined surface is treated here as a dynamic system. An investigation is carried out to establish a relationship between the characteristics of cutting force fluctuations that cause vibration response of the tool-workpiece system and the formation of surface in face cutting by sintered carbide cutting tool. Cutting force is measured and analyzed in frequency domain. The power spectral densities of cutting force give a useful information in surface generation and it can be used to find out the control factor of surface roughness. The terms, PSD ratio & Normalized spindle frequency PSD, are defined and when the value of power in spindle frequency is absolutely little but relatively large, it is obtained high accuracy surface roughness. The aim of this research is to find surface profile by measured and analyzed cutting force signals. The simulation of surface generation gives the comprechension of its mechanism and help to predict and control the surface quality. In this study, it is suggested what informations about surface generation can be acquired from the cuttuing force signal and an way of generating a better surface.

• Coupled systems mechanics
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• v.2 no.1
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• pp.23-51
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• 2013

An analytical algorithm for the estimation of the resistance forces exerted on the dipper of a cable shovel and the specific energy consumed in the cutting-loading process is presented. Forces due to payload and to cutting of geomaterials under given initial conditions, cutting trajectory of the bucket, bucket's design, and geomaterial properties are analytically computed. The excavation process has been modeled by means of a kinematical shovel model, as well as of dynamic payload and cutting resistance models. For the calculation of the cutting forces, a logsandwich passive failure mechanism of the geomaterial is considered, as has been found by considering that a slip surface propagates like a mixed mode crack. Subsequently, the Upper-Bound theorem of Limit Analysis Theory is applied for the approximate calculation of the maximum reacting forces exerted on the dipper of the cable shovel. This algorithm has been implemented into an Excel$^{TM}$ spreadsheet to facilitate user-friendly, "transparent" calculations and built-in data analysis techniques. Its use is demonstrated with a realistic application of a medium-sized shovel. It was found, among others, that the specific energy of cutting exhibits a size effect, such that it decreases as the (-1)-power of the cutting depth for the considered example application.

• Tribology and Lubricants
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• v.11 no.5
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• pp.99-107
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• 1995

This paper reported research results to develop an algorithm of on-lin evaluation of surface profiles and roughness generated by turning. The developed module consisted of computer simulation of surface profiles using mechanism of cutting mark formation and cutting vibrations, and online measurement of cutting vibrations. The relative cutting vibrations between tool and worpkiece were measured through an inductance pickup at the rate of one sample per rotation of the workpiece. The sampling process was monitored using an encoder to avoid conceling out the phase lag between waves. The digital cutting signals from the Analog-to-Digital converter were transferred to the simulation module of surface profile where the surface profiles were generated. The developed algorithm or surface generation in a hard turning was analyzed through computer simulations to consider the stochastic and dynamic nature of cutting process. Cutting tests were performed using AISI 304 Stainless Steel and carbide inserts in practical range of cutting conditions. Experimental results showed good correlation between the surface profiles and roughness obtained using the developed algorithm and the surface texture measured using a surface profilemeter. The research provided the feasibility to monitor surface characteristics during tribelogical tests considering wear effect on surface texture in machining.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.297-301
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• 2002

High-speed machining generates concenter thermal/frictional damage at the cutting ed rapidly decreases the tool life. This paper I at determining the effect of cutter orienter the cutting environment on tool life, tool mechanism when down milling. In this paper, experiments were carried out in various tool and cutting environments, such as dry, wet compressed chilled air, tool life were measu evaluate machinability in high-speed milli difficult-to-cut material and die steel, Tool measured in horizontal upwards, horiz downwards, vertical upwards and vert downwards. In addition, tool life was measur dry, wet and compressed chilled air. For this a compressed chi1led-air system was manufact The results show that a horizontal cutter ori provided a longer tool life than a vertical orientation. With respect to the cutting envi compressed chilled air increased tool life. H the wet condition decreased tool life due thermal shock caused by excessive cooling high-speed mill ins and the compressed chilled had little effect.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.5
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• pp.419-424
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• 2002

After the patterning and probe process of wafer have been achieved, the dicing processing is necessary to separate chips from a wafer. The dicing process cuts a semiconductor wafer to lengthwise and crosswise directions to make many chips. The existing general dicing method is the mechanical cutting using a narrow circular rotating blade impregnated diamond particles or laser cutting. Inferior goods can be made by the mechanical or laser cutting unless several parameters such as blade, wafer, cutting water and cutting conditions are properly set. Moreover, we can not apply these general dicing method to that of GaN wafer, because the GaN wafer is harder than general semiconductor wafers such as GaAs, GaAsP, AIGaAs and so forth. In order to overcome these problems, this paper describes a new wafer dicing method using fixed diamond scriber and precision servo mechanism.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.3
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• pp.39-44
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• 2002

As laser cutting process is widely used in industry, an automated on-line process control system has become very important. In this paper, development of a laser cutting monitoring system, which is regarded as the fundamental step toward automation of the process, is presented. Acoustic emission and an artificial neural network were used for the monitoring system. With given process Parameters including laser power and scanning speed the system can predict the suitability of laser beam for the cutting or a stainless steel (STS304) plate.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.10
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• pp.208-213
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• 2001

High speed milling(HSM) is one of the emerging cutting process having tremendous potential not only in increased metal removal rates but also in improved surface finish, burr free edge, dimensional accuracy and a virtually stress free component after machining. The High efficiency and accuracy in machining of die/mold materials can be obtained in high speed machining, so it is necessary to analytic the mechanism of high speed cutting process : cutting force, acoustic emission signal.

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.48-57
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• 1979

In order to obtain a standard reference for designing an adequate power rice transplanter, the cutting forces depending upon variety of seedling, sowing density, seedling age and soil moisture content of mat-type seedling were measured by the rice transplanter installed with force measuring device of dynamic strain gage system in the laboratory. The result of this study are summarized as follows : 1. Cutting velocity and acceleration transplanting hoe obtained from jinematic analysis of planting mechanism was 1.32m/sec and 81.5m/$sec^2$ when planting crank-shaft rpm was 160. 2. Little difference between cutting forces on 30-days old seelings of japonica and Indica type was observed, as the cutting forces determined were 2.0kg per hill for Japonica type and 2.1kg per hill for Indica type. 3. Cutting forces determined on 40-days old seedlings were 2.5kg, 2.3kg, 3.1kg and 2.9kg per hill for Milyang No.15, Tongil, Akibare and Milyang No.23 compared to the other varieties. 4. The cutting force was not greatly affected by the sowing densities , only five percent of differences were observed epending upon the sowing densities. 5. Cutting forces were 2.7kg and 2.0kg per hill on 40-days old seedlings and 30-days old seedlings respectively. About 38 percent of more forces was required in cutting 40-days old seedling than in cutting 30-days old seedlings. 6. More cutting forces were required as soil moisture content of mat-type seedling was decreased. 7. Root length after cutting by the planting hoe and their relationships with soil moisture content on 30-days old seedlings, are as follows ; $y=4.147-11.384x+ 28.854x^2$ where , $y$=root length after cutting. (cm) , $x$=soil ture content of mat type seedlings.(%, d.b.) 8. Cutting forces were varied with the width of cuttings ; those on 40-days old mat type seedlings were 2.7kg and 2.2kg per hill when cutting with 14 mm and 10mm of width respectively, about 32 percent of more forces was required when cuting with 14mm of width compared to 10mm of width.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.4
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• pp.604-610
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• 1989

This paper is concerned with the machinability of fine ceramics(Al$_{2}$O$_{3}$) by using sintered diamond tools. For this purpose, ceramics cutting experiments under various cutting conditions such as cutting speed, feed rate, and others were carried out. The main results are follows : (1) During the cutting of fine ceramics, the used tools were found to be slightly chattering at cutting speed of 70m/min, and at cutting speed of higher than this I found the fine ceramics difficult to be cut. (2) When I used a tool with large nose radius, there occured a small amount of wear on the flank of the tool. However, at the early stage of fine ceramics cutting, the tools with smaller nose radii were required mainly to prevent the chipping of the ceramics. (3) When the materials were dry-cut, the appropriate cutting speel was found to be lower than 40m/min, and when the materials were dry-cut, I could cut them without any difficulty even at the speed of 70m/min, the surface roughness of ceramics cut at the speed of 70m/min was considerly fine. (4) It is generally believed that the principal cutting force is the largest in the case of steels cutting, but I found the thrust cutting force to be larger than any other cutting forces in the case of ceramics cutting.