• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.209-210
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• 2010

• Journal of the Korean Society for Precision Engineering
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• v.5 no.1
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• pp.50-62
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• 1988

An experimental investigation of the machining characteristics of compact vermicular cast iron whose matrix were formulated under two kinds of annealing conditions has been conducted. The various characteristics of the machinability of CA cast iron depending upon its matrix and cutting condition have been obtained from the experiment. The results are as follow. As depth of cut increases, the shear stress slightly decreases in order $P_1, \P_2, \P_3$ which are classified by ferrite matrix of CV cast iron. As depth of cut increases, the normal stress increases, and annealing effect in heavy cutting is smaller than that in light cutting. The cutting energy slightly decreases, as depth of cut increases and the effect of annealing on cutting energy in light cutting is higher than that in heavy cutting. The cutting equation in this study are as follow. $P_1\:\2{\phi}\ + \1.49({\beta} - {\alpha} )=84^{\circ}$ $P_2\:\2{\phi}\ + \1.36({\beta} - {\alpha} )=82^{\circ}$ $P_3\:\2{\phi}\ + \1.34({\beta} - {\alpha} )=79^{\circ}$ Machining constants in this study for $P_1, P_2, P_3$give $74^{\circ} , 66^{\circ}, 61^{\circ}$ Tool wear increases as depth of cut increases, and decreases as ferrit matrix increases.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.9-18
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• 2021

The cutting force in a cutting simulation is determined by the cutting conditions, such as cutting speed, feed rate, and depth of cut. The cutting force changes, depending on the material and cutting conditions, and is affected by the heat generated during cutting. The physical properties for predicting the cutting force use constitutive equations as functions of the hardening term, rate-hardening term, and thermal-softening term. To accurately predict the thermal properties, it is necessary to accurately predict the thermal-softening coefficient. In this study, the thermal-softening coefficient was determined, and the cutting force was predicted, using the response-surface method with the cutting conditions and the thermal-softening coefficient as factors.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.1
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• pp.74-81
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• 1987

The orthogonal cutting method of the nodular graphite cast iron in the lathe turning, whose structure were formulated under two kinds of annealing conditions, has been experimentally studied and the results investigated. The various characteristics of machinabilities of the nodular cast iron, depending upon its structure, have been obtained from the results as follows. (1) As depth of cut increases, the shearing strain decreases and tend gradually to increase with increase of ferrite matrix. (2) As depth of cut increases, the shearing stress slightly decreases for P$_{1}$, but it tends to increase for both of P$_{2}$ and P$_{3}$ under the same condition. The annealing effect in the process of light cutting was found to be greater than heavy cutting. (3) The cutting energy slightly decreases with the increassing of the depth of cut, and the effect of decreasing the cutting energy by the annealing is higer the light cutting than the heavy cutting. (4) The cutting equations as follow. P$_{1}$ : 2.phi.+1.58(.betha.-alpha.)=92 deg. P$_{2}$ : 2.phi.+1.40(.betha.-alpha.)=84 deg. P$_{3}$ : 2.phi.+1.37(.betha.-alpha.)=82 deg. (5) The machining constants for P$_{1}$, P$_{2}$ and P$_{3}$ which are the test-pieces in this study and classified according to the containing quantity of ferrite matrix given respectively in 78deg., 70 deg., and 68 deg. From these it can be known that the machining constants slightly decreases with increasing of the quantity of ferrite matrix contained in the nodular graphite cast iron.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.3
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• pp.29-35
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• 2006

Various types of elliptical motions are generated by PZT mechanism which is composed of two parallel piezoelectric actuators. Elliptical vibration cutting(EVC) is obtained by attaching single crystal diamond cutting tool to the mechanism, and V-grooving for Brass and Aluminum is carried out by applying the EVC. It is experimentally observed that the cutting force in the process of the EVC reduces compared to the ordinary non-vibration cutting, which is due to the decrease of undeformed chip thickness and frictional force between the tool and chip. Ultrasonic elliptical vibration cutting(UEVC) suppresses burr formation and decreases cutting force still more, so UEVC makes it possible to enhance the shape accuracy of machined surface.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.941-946
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• 2018

Currently, due to the development of technology, the industry is proceeding with the development of advanced materials with high performance such as light weight, heat resistance and electric conductivity. Carbon Fiber Reinforced Plastics (CFRP) is an excellent material with high heat resistance, high strength and thermal shock resistance. In order to obtain excellent hole shape in CFRP drilling, we compared the modified drill shape and the conventional carbide drill. On the other hand, we determine the proper helix angle by observing the CFRP surface according to the helix angle at the trimming of the end mill proceeding after the hole machining.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.211-212
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• 2010

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.107-114
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• 2017

A turbocharger is an engine supercharger that is driven by exhaust gas. It improves the output and fuel efficiency by increasing the charging efficiency of the mixture gas, which is achieved by changing the rotatory power of the turbine connected to the exhaust passage. It is important to control the supercharging for this purpose. A nozzle slide joint is one of the core parts. Austenitic stainless steel is currently used as the material for this part, and its excellent mechanical properties include high heat resistance and corrosion resistance. However, because of its poor machinability, there are many difficulties in producing products with complicated shapes. Machining is used in the production of nozzle slide joints for high dimensional accuracy after metal powder injection molding. As design variables in this study, we investigated the sintering temperature, product stress, deformation rate, radius of curvature of the punch, and angle of the chamfer punch, which are related to the strain and shapes. The goal is to suggest a forming process using Nitronic 60 that does not require machining to manufacture a nozzle slide joint for a turbocharger. Accordingly, we determined the best process environment using finite-element analysis, the signal-noise ratio, and the Taguchi method for experiment design. The relative density and hydrostatic pressure of the final product were in accordance with the results of the finite element analysis. Therefore, we conclude that the Taguchi method can be applied to the design process of metal powder injection molding.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.8
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• pp.1910-1920
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• 1993

An experimental study to investigate the unconventional chip formation called triangulation of chip in cutting with a SPRT (self-propelled rotary tool) is performed using acoustic emission (AE) signal analysis. In doing that, a quantitative model of the AE RMS signal in triangulation with a SPRT is first developed. The predicted results from this model show good correlation between the AE RMS signal and the general characteristics of triangular chip formation. Then, effects of various process parameters such as cutting conditions (cutting speed, depth of cut, oblique angle and normal rake angle) and the work material properties on the chip formation in cutting with a SPRT are explored. Special attention is paid to the work material properties which are found to have significant effects on triangulation.

• Proceedings of the Safety Management and Science Conference
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• 2000.05a
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• pp.241-248
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• 2000

Increased complexity of products and their manufacturing processing demans higher quality control and monitoring than ever before. Therefore, flexible automatization or flexible manufacturing systems (FMS) offer numerous advantages over alternative manufacturing methods. In this state, a in-process monitoring is one of the important flexible automation system. And as use of NC and CNC machine tool has been increasing, cutting work has automating and it is necessary to develop the automatic production system combined a couple of machine tool. Thus, in this paper to search examination it can measure the tool wear and the tool life and can be more practical research subject.