• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.365-370
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• 1999

SKD11 is one of the most difficult workpiece for machining, so it is necessary to evaluate the machining characteristics of SKD11. The workpiece was made to be the pipe form and heat-treated to HRC45. In this paper, the orthogonal cutting experiment of this material was carried out with TiAlN coated WC cutting tool of 4 kinds of rake angle. After cutting experiment, cutting characteristics of SKD11 were investigated according to variation of cutting speed, feedrate and rake angle.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.63-68
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• 1996

In this study, the effect of tool rake angles and the change of cutting conditions on specific cutting pressure in face milling is investigated. The cutting force in face milling is predicted from the double cutting edge model in 3-dimensional cutting. Conventional specific cutting pressure model is modified by considering the variation of tool rake angles. Effectiveness of the modified cutting force model is verified by the experiments using special face milling cutters with different cutter pockets and various rake angles. From the comparison of the pressented model and the specific cutting pressure, it is shown that the axial force can be predicted by the tangential and redial forces without the knowledge of friction angle and shear angle. Also, the relation between specific cutting pressure and cutting cindition including feedrate, cutting velocity and depth of cut is studied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.769-770
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• 2011

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.1
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• pp.171-181
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• 2001

Recently, the development of CNC machine tools seems to bring about progressional high speed, precision and automation in cutting processing, but is unlikely to avoid the generation of burr arising from plastic deformation, which may result in deterioration of improvement in the precision and productivty of products. In this study, Experiment has been carried out to prevent and decrease the grinding burr under various working conditions ; working speed, side cutting edge, back rake angle, disengage angel.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.393-398
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• 2001

The technique of high speed machining is widely studied in machining fields, because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool for high speed machining in not close behind that of machine tool. In this study, several types flat endmill is prepared for obtaining data according to tool shape. Especially, we concentrated in helix angle, number of cutting edge, rake angle and relief angle. Machinability is measured by cutting force, tool life, tool wear, chip shape and surface roughness according to cutting length. 3-axis cutting forces are acquired from the invented tool dynamometer for high speed machining. Particularly, we found out that the axial cutting force waveform has a good relation with tool wear features. By above results, it is suggested the endmill tool with $45^{\circ}$ helix angle, 6 cutting edge, $-15^{\circ}$ rake angle and $12^{\circ}$ relief angle be suitable for high speed machining

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.7-12
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• 2009

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. Generally, ceramics are machined using conventional method such as grinding and polishing. However these processes are generally costly and have low MRR(material removal rate). 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 10 and 15%. The purpose of this study is an analysis of endmill's rake angle for appropriate tools design and manufacturing for the machinable ceramics. In this study, Experimental works are executed to measure cutting force, surface roughness, tool fracture, on different axial rake angle of endmills. Cutting parameters, namely, feed, cutting speed and depth of cut are used to accomplish purpose of this paper. Required experiments are performed, and the results are investigated.

• Economic and Environmental Geology
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• v.31 no.6
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• pp.547-555
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• 1998

A new trigonometrical method for calculating total slip (T) of faulting is presented. The parameters for the calculations are used rake of fault striation, strike and dip of fault and of index planar structure such as bedding plane. The faults are groupped into three types. The direction of plunging of fault striation is out of a range ${\pm}90^{\circ}$ to the bedding dip direction in $360^{\circ}$ system, which is groupped into the type I. Meanwhile, the case of the direction lies in the above range can be separated into two different types, type II and type III, according to relative largeness of the angles rake of fault striation and i (see text). The type II has smaller rake than angle i and the type III has larger rake than angle i. Here I propose a few equations for calculating not only total slip (T) but strike slip (L) or dip slip (S) of the faulting. The equations are adapted selectively to the types of fault mentioned before. The limitation of the method is that the equations do not fit to polyphase faulting.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.11
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• pp.2664-2675
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• 1993

In this paper, the effects of chip breaker configuration on cutting forces for various cutting conditions are investigated and a method for predicting cutting forces effectively for chip breaker insert in milling is described. Based on the shear plane model and the relevant equations already existing for the relation among the parameters, the method makes use of the analytic geometric approach considering the configuration of cutting too by a 3-dimensional coordinate transformation matrix. The groove type chip breaker insert is modeled to be a double rake insert, represented by the first radial rake angle, the second radial rake angle and the length of land, and the program analyzing the cutting forces is developed. The program capability is verified by comparing the results with the experimental ones for a single cutter; and in case of primary cutting forces, the results of simulation and experiments agree very well showing 2%~16.7% difference within the feed rate range investigated.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.3
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• pp.66-75
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• 1987

The determination of stress distributions on the rake face of tool are important to understand the mechanism of metal cutting. For this reason, many researchers have been payed much effort to analyize machining stress distribution on the rake face. The author's photoelastic experiment has shown that the stress distributions on a rake face can be obtained photoelastically by using a specially designed tool made of epoxy resin plate, and also, Stress Intensity Factors $k_{I}$, $k_{II}$ and Crack Extension Angle can be deter mined by using Linear Elastic Fracture Mechanics.ics..

• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.133-138
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• 2002

The technique of high speed machining is widely studied in machining fields, because the high efficiency and accuracy in machining can be obtained in high speed machining. Unfortunately the development of tool fur high speed machining in not close behind that of machine tool. In this study, 10 types flat endmill is prepared for obtaining data according to tool shape. Especially, we concentrated in helix angle, number of cutting edge and rake angle. Cutting condition is selected for several experiments and measuring cutting farce, tool life, tool wear and chip shape according to cutting length. 3-axis cutting farces are acquired from the tool dynamometer with high natural frequency, as the conventional tool dynamometer (9257B, Kistler) has cannot measure the state of high frequency force. Particularly, we found out that the axial cutting force waveform has a good relation with tool wear features. And flow is interrupted at the beginning of cutting by the decrease of rake angle. By above results. it is suggested the endmill tool with 45$^{\circ}$helix angle, 6 cutting edge and -15$^{\circ}$rake angle is suitable for high speed machining.