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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of Materials Processing
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Journal DOI :
The Korean Society for Technology of Plasticity
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Volume & Issues
Volume 14, Issue 9 - Dec 2005
Volume 14, Issue 8 - Nov 2005
Volume 14, Issue 7 - Oct 2005
Volume 14, Issue 6 - Sep 2005
Volume 14, Issue 5 - Aug 2005
Volume 14, Issue 4 - Jul 2005
Volume 14, Issue 3 - Jun 2005
Volume 14, Issue 2 - Apr 2005
Volume 14, Issue 1 - Feb 2005
Selecting the target year
Principle and Recent Trend of Rapid Prototyping Technology
Kim H. C. ; Park S. H. ; Yang D. Y. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 187~199
DOI : 10.5228/KSPP.2005.14.3.187
A Study on Machining Method of Multi-Electrode
Jung T. S. ; Yoo S. W. ; Yang J. S. ; Heo Y. M. ; Kim K. S. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 200~206
DOI : 10.5228/KSPP.2005.14.3.200
In general, a lot of small electrode is needed for making precision injection molds, such as cell phone mold and precision connector mold, because of the limitations of NC milling process. Those small electrodes usually have very simple shapes and the actual cutting time is so short, but many NC programs and set-up process, a very complicated and time consuming Job, are needed for each electrode. This paper deals the method for increasing the productivity of machining electrodes. In this work, the process standardization of machining electrode was done and special jig fer machining small electrodes was developed. Automatic tool path optimization software was also developed to minimize tool changing time. In addition, in-line cutting tool measuring system was adopted. The productivity of machining for small electrode has been increased up to
A Progressive Fine Blanking Process Design for Forming of Carrier Plate
Kim J. D. ; Kang J. J. ; Hong S. K. ; Kim B. J. ; Kim H. K. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 207~214
DOI : 10.5228/KSPP.2005.14.3.207
Blanking process is widely used fur producing various structural parts. However, fine blanking technology is frequently used as a single step blanking operation with clean cut surface of a sheared surface because the fractured surface of parts causes serious problems in the final product and therefore it must be removed by the post-processing in case of the conventional blanking. In the present investigation, a fine blanking process was designed within the framework of progressive die to produce a carrier plate assembled within the auto transmission. Finite element analysis of the shearing behavior at the respective stage of the progressive fine blanking was conducted to validate the designed die parameters. Finally the designed progressive fine blanking process was experimentally evaluated by using the machined die.
Heat Treatment Analysis on Low-Alloy Steel
Choi Y. S. ; Kwak S. Y. ; Choi J. K. ; Kim J. T. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 215~223
DOI : 10.5228/KSPP.2005.14.3.215
A numerical analysis program is developed by FDM scheme for the prediction of microstructural transformation during heat treatment of steels. In this study, multi-phase model was used fur description of diffusional austenite transformations in low-alloy hypoeutectoid steels during cooling after austenitization. A fundamental property of the model consisting of coupled differential equations is that by taking into account the rate of austenite grain growth, it permits the prediction of the progress of ferrite, pearlite, and bainite transformations simultaneously during quenching and estimate the amount of martensite also by using K-M eq. In order to simulate the microstructural evolution during tempering process, another Avrami-type eq. was adopted and method for vickers hardness prediction was also proposed. To verify the developed program, the calculated results are compared with experimental ones of casting product. Based on these results, newly designed heat treatment process is proposed and it was proved to be effective for industry.
Study for Permanent Mold Design Technology and Porosity Defect Prediction Method by Multi-Phase Flow Numerical Simulations
Choi Y. S. ; Cho I. S. ; Hwang H. Y. ; Choi J. K. ; Hong J. H. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 224~232
DOI : 10.5228/KSPP.2005.14.3.224
The high-pressure die-casting is one of the most effective methods to produce a large amount of products in short cycle time. This process, however, has a problem that the gas porosity defect appears easily. The generation of gas porosity is known mainly due to the air entrapment during the injection stage. Most of numerical simulations for the molten metal flow pattern observations have done in the treating of one phase fluid flow but the gas-liquid interface is essentially multi- phase phenomenon. In this paper, the two-phase fluid flow numerical simulation methods have been adapted to predict the gas porosity generations in the molten metal. The accuracy and the usefulness of the new simulation module have been emphasized and verified through some comparison experiments.
Blow Characteristics in Extrusion Blow Molding for Operational Conditions
Jun Jae Hoo ; Pae Youlee ; Lyu Min-Young ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 233~238
DOI : 10.5228/KSPP.2005.14.3.233
Blow molding is divided into three categories, injection stretch blow molding, injection blow molding, and extrusion or direct blow molding. Extrusion blow molding has been studied experimentally to characterize the blowing behavior of parison. Blow conditions such as blowing temperature and cooling time were the experimental variables in this blowing experiment. Wall thickness of the lower part of blow molded sample was thicker than that of the upper part because of the sagging of parison during extrusion process. As temperature increases the wall thickness and the weight of blow molded sample decreased. No thickness variations in the blowing sample were observed according to the cooling time. The lower part of the sample showed high degree of crystallinity compare with the upper part of the sample. Thus the lower part of the sample was strong mechanically and structurally. It was recognized that the uniform wall thickness could not be obtained by only controlling the operational conditions. Parison variator should be introduced to get uniform wall thickness of parison and subsequently produce uniform wall thickness of blow molded product.
Development of The Die & Mould-Design System for The Productivity Increase of Die and Mould
Shin J. S. ; Huh Y. M. ; Yoon G. S. ; Kim Y. J. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 239~244
DOI : 10.5228/KSPP.2005.14.3.239
The die & mould-design system fur the productivity increase is developed by our company. This system is made by UG API and constructs the standard through DB of parts of die & mould. Besides, the result of engineering analytic method is reflected in the design process in this system and the product precision is secured by On Machine Measurement method. Therefore, the ground of quality improvement and process innovation is solidified by the developed system and the competitiveness of die & mould manufacturing is intensified.
A Study on Lenticular Lens Mold Fabrication by Shaping
Je T. J. ; Lee E. S. ; Shim Y. S. ; Kim E. Z. ; Na K. H. ; Choi D. S. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 245~250
DOI : 10.5228/KSPP.2005.14.3.245
Recently, micro machining technology for high precision mold becomes more interested for mass production of high performance optical parts micro-grooved on the surface, which is under very active development due to its effectiveness in the view point of optical performance. Mechanical micro machining technology now has more competitiveness on lithography, MEMS or LIGA processes which have some problems to fabricate especially cylinder type of groove in such as lenticular lens for illumination angle modulation system. In this study. a lenticular lens mold with U-type micro groove is fabricated making utilizing of the benefit of the mechanical micro machining technology. A shaping machining process is adapted using 3 axis degree of freedom micro machining system and single crystal natural diamond tool. A brass and a electroless nickel materials are used for mold fabrication. Machining force, chip shape and machined surface are investigated from the experiment and an optimal machining condition is found based on the examined problems from the micro cutting process.
Fabrication of 3-D Micro Structure and Micro Tool Using MEDM
Kim B. H. ; Yi S. M. ; Chu C. N. ; Kang Y. H. ; Choi T. H. ; Park H. J. ; Lee Y. S. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 251~256
DOI : 10.5228/KSPP.2005.14.3.251
3-D micro structures and micro tools were fabricated using Micro Electrical Discharge Machining (MEDM). To make micro structures, micro electrical discharge milling process was applied. During micro electrical discharge milling, electrode (tool) worn in the both axial and radial direction. To compensate tool wear which has significant influence on machining accuracy, machining path overlapping was proposed. Machining characteristics of micro electrical discharge milling was investigated in considering of depth of cut and capacitance of discharge circuit. Micro complex shaped tools were also fabricated using REDM (reverse electrical discharge machining). Sacrificial electrodes were machined through electrical discharge milling process and were used as electrode to make micro tools. Using this process several micro tools shape of `ㄷ`, `ㅁ` and `o` were fabricated. With these complex shaped tools, micro machining was successfully applied repeatedly.
A Study on the Shear Deformation Behavior of Inner Structure-Bonded Sheet Metal
Kim J. Y. ; Chung W. J. ; Yang D. Y. ; Kim J. H. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 257~262
DOI : 10.5228/KSPP.2005.14.3.257
In order to improve the quality of the sheared surface in cutting of inner structure bonded sheet metal the cut-off operation is mainly investigated, which is the typical shearing process in sheet metal forming technology. The sandwich sheet metals considered have inner structure which is constructed in the form of crimped expanded metal and woven metal. The inner structure is bonded between solid sheet by resistance welding or adhesive bonding. The shearing process is visualized by the computer vision system installed in front of the cut-off die and the sheared surface is measured and quantitatively compared with the help of the optical microscope after cut-off operation. From test results we found that the influence of sheared position can be observed and explained clearly and this result can be utilized to get the better sheared surface.
Beating Channel Layout Design and Evaluation Technology for SMC Molds
Heo Y. M. ; Ko Y. B. ; Lee J. H. ; Lee S. H. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 263~268
DOI : 10.5228/KSPP.2005.14.3.263
Heating channel layout design and evaluation technology for SMC molding system was investigated in this work. Traditional rules of cooling channel design in injection molding were applied to the present work. Finite element thermal analysis with
was performed to evaluate the temperature distribution of SHC mold surface. SMC mold was manufactured to evaluate the effect of a proposed heating channel layout system on the temperature distribution of SMC mold surface and infrared camera was applied to a measurement of temperature distribution. It was shown that infrared camera application was possible in a measurement of temperature distribution on SHC mold surface.
The Warpage Reduction for Intake Manifold Product
Lee S. H. ; Shin K. H. ; Yoon G. S. ; Jung W. C. ; Jung T. S. ; Heo Y. M. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 269~276
DOI : 10.5228/KSPP.2005.14.3.269
The purpose of this research is the warpage reduction for intake-manifold which is made to the injection molding. Intake-manifold is assembling to ultra sonic welding after forming. Therefore deformation is influence on the performance and manufacture to intake-manifold product. Location and number of gates, filling time, mold temperature, packing time, packing pressure and cooling time are factors that affect the deformation of injection molding product. Therefore, the injection molding characteristics of intake-manifold and the estimated deformation are detected by CAE analysis and compare measuring data in this study.
Evaluation of Punching Process Variables Influencing Micro Via-hole Quality of LTCC Green Sheet
Baek S. W. ; Rhim S. H. ; Oh S. I. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 277~281
DOI : 10.5228/KSPP.2005.14.3.277
LTCC(Low temperature co-fired ceramic) is being recognized as a significant packaging material of electrical devices for the advantages such as relatively low temperature being needed for process, low conductor resistance and high printing resolution. In the process of LTCC electrical devices, the punched via-hole quality is one of the most important factors on the performance of the device. However, its mechanism is very complicated and optimization of the process seems difficult. In this paper, to clarify the process, via-hole punching experiments were carried out and the punched holes were examined in terms of their burr formation. The effects of thickness of PET sheet, ceramic sheet and punch-to- die clearance on via-hole quality were also discussed. Optimum process conditions are proposed and a factor
is introduced to express effect of the process variables.
A Study on the Simulation and DSF Molding of V-groove Type Light Guide for a Backlight Unit
Cho K. H. ; Yoon K. H. ;
Transactions of Materials Processing, volume 14, issue 3, 2005, Pages 282~290
DOI : 10.5228/KSPP.2005.14.3.282
Nowadays, TFT-LCD is widely used as display unit of many digital devices. And, the backlight unit(BLU) is used as a light source of TFT-LCD module. In the backlight unit, the most important component is a light guide, which guides the input light to the TFT-LCD module uniformly. Recently, many researchers have focused on improving the efficiency of BLU by changing the design and structure of a light guide. In the present paper, a series of simulation was performed to find the optimal luminance distribution of emanated light from the given geometry as the first step. From the results of simulations for the light guide with given V-groove pattern, the emanated light from it is mostly affected by the groove angle. In the case of acute angle, about 74 degrees was found as optimal angle to satisfy the restrictions of angular luminance distribution, FWHM, the maximum luminance, etc. However, as far as the average luminance value was concerned, the case of 120 degrees(abtuse angle) was found to be the best while prism films were added to the BLU. As a next step the light guide samples of 74 and 120 degrees were manufactured by DSF method, which was recently proposed by the authors. Of course, most of design parameters were chosen by the aid of simulation results. Finally, the results of average luminance values were compared between the simulation and DSF molded samples.