• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.5
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• pp.129-134
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• 2013

Titanium used in industry has been widely applied for aerospace important parts and automobile important parts, etc. because the titanium is higher in strength compared to the steel and light in weight compared to the steel. This study is to investigate the effect of cutting tool cooling method and cutting time on the spindle speed and feed rate of vertical machining center as a parameter to find the rough cutting time in the medium speed cutting machining of the titanium alloy. It is found that the cutting machining heat are increased as the feed rate, cutting time and spindle speed are raised.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.24-31
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• 2003

In the gas cutting of plate steel, the quality of the cut surfaces and sections is strongly dependent on the cutting conditions such as cutting speed, kerf width, plate thickness, material, distance between tip and specimen, and cutting oxygen pressure etc. The cutting tests of plate steel were carried out using CNC gas cutting machine. This paper deals with cut surface and section characteristics of plate steel in CNC gas cutting. Both top and bottom widths of kerf, the surface roughness(Ra, Rmax) of cutting surfaces are measured under various cutting conditions such as cutting speed, material, distance between tip and specimen, and cutting thickness. The photographs of cut surface and cut section are also analyzed under various cutting conditions.

• Journal of the Korean Wood Science and Technology
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• v.16 no.4
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• pp.61-69
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• 1988

Recently the automization of wood manufacturing and the development of CNC machine tools becomes the center of interest. Cutting mechanism, tool wear and the roughness of machined surface have been studied. In the studies about wood for special uses, concrete data of cutting is desired. While Pinus densiflora is characterized that heartwood develops as age increases, Chunyang District has the characteristic of strength, red color, relatively regular chap and high heartwood - percentage. But there is no data about cutting this wood, Chunyang District. In this study face milling by sintered carbide tool was excuted to Chunyang District. Cutting force, Surface roughness and states were investigated with regard to cutting speed. Example results were as follows; 1) Mean cutting resistance against lateral component force and longitudinal component force decreased rapidly up to cutting speed of 155 m/min, and remains constant above this speed. 2) The surface roughness of cutting surface lowered as cutting speed increased, regardless of fiber formation. Radial rougness of fiber is larger than lineal surface roughness. 3) Increase in Cutting speed made machining mark restrained. Down-milling showed larger marks than up-milling.

• 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

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.5
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• pp.1055-1062
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• 1988

The characteristics of tool wear and the machinability in cutting of GFRP have been studied. The wear behavior of carbide insert tools(P20, M10, K10) and Cermet in TiC grade was studied by turning of changing the cutting condition. Machinability could be estimated as the following empirical formula, CT$^{n}$ =W The main results obtained are as follows: (1) Dependence of rate of tool wear on cutting speed; with increases of cutting speed, the rate of tool wear initially increases gradually(1st range), then it increases proportionally to cutting speed(2nd range), and finally the rate is constant(3rd range). (2) When the contact length has a main, effect on tool wear, the cutting speed does nit affect the tool wear. On the contrary, the cutting speed has a main effect on tool wear, the contact length does not affect the tool wear. (3) The order of machinability is K10, M10, P20 and Cermet in TiC grade.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.4
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• pp.21-27
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• 2005

Recently researches for high speed machining have been actively performed. Few analytical studies, however, have been published. In this paper, a model of cutting forces is analytically studied to predict cutting characteristics in end mill process, especially considering both feed rate and spindle speed. The developed cutting model is based on Oxley's machining theory, which predicts the cutting forces from input data of workpiece material properties, tool geometry and cutting conditions. Experimental verification has been performed to verify the predictive cutting force model using tool dynamometer. It has been found that the simulation results substantially agree with experimental results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.806-809
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• 2000

The factors which can improve tool life in machining are consisted of tool geometries, tool materials, coating methods. cutting environments, cutting conditions and so on. Cutting speed in cutting conditions is one of the important factors which can directly influence on the tool life. This paper deals the machinability which is concerned about the cutting direction and the tilt angle of fret form surface in hot die steel(STD I I). The NC datum were analysrd and the effective tool diameters were calculated according to the change of tilt angle the program which can continue the cutting speed with the change of spindle revolution is developed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.965-969
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• 1997

Due to the high feed rate,high speed machining (HSM) provide a great potential of rationalization for the machining Dies and Moulds. But determination of cutting condition is very difficult, because cutting mechanism of high speed machining is very complicated,especially using ball end-mill. This paoer gives a report on selection of the optimal cutting condition to improve the machining efficiency, And optimal machining condition is determined through the cutting force, FFT analysis of cutting force and surface roughness according to the cutting condition. Based on this experiment result,wear process and machining characteristics are evaluated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.778-781
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• 2004

As the technique of high-speed end-milling is widely adopted to in machining field. The investigation for microscopic precision of workpiece is necessary for machinability evolution. In this study, cutting force, cutting temperature and microhardness were investigated to evaluate damaged layer in conventional machining and high-speed machining. Damaged layer was measured using optical microscope. The thickness of damaged layer depends on cutting process parameters, specially feed per tooth and radial depth. It is obtained that the characteristics of damaged layer is high-speed machining better than conventional machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.19-22
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• 1997

The objective of this research is to use an analytical and experimental approach to develop optimal tool geometry for high speed machining. The tool geometry parameters and cutting process have complex relationships. Until now, numerous cutting tests were needed to acquire optimal design of endmill for the purpose of high speed machining, dut to the insufficient knowledge about process in high speed machining. In order to improve the cutting ability of endmill, a model for optimal cutter shape was developed to minimize resultant cutting force by combing cutting force and wear test and surface roughness test from optimized and conventional cutter with the same cutting condition. Using various tools with different geometry, relationships between the tool geometry parameter, rake angle, clearance angle, lengh of cutter have been stuied.