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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Transactions of Materials Processing
Journal Basic Information
Journal DOI :
The Korean Society for Technology of Plasticity
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Volume & Issues
Volume 18, Issue 8 - Dec 2009
Volume 18, Issue 7 - Nov 2009
Volume 18, Issue 6 - Oct 2009
Volume 18, Issue 5 - Aug 2009
Volume 18, Issue 4 - Jul 2009
Volume 18, Issue 3 - Jun 2009
Volume 18, Issue 2 - Apr 2009
Volume 18, Issue 1 - Feb 2009
Selecting the target year
History of Engineering Plasticity and The Pioneers
Osakada, K. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 193~209
DOI : 10.5228/KSPP.2009.18.3.193
Springback Control of an Automotive Surround Molding Part Using Automatic Die Compensation Module
Lee, D.Y. ; Choi, B.S. ; Hwang, J.H. ; Baek, I.K. ; Choi, K.Y. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 210~216
DOI : 10.5228/KSPP.2009.18.3.210
Springback, an elastic material recovery after the unloading of stamping tools, causes variations and inconsistencies of final part dimensions. Recently, narrow and long surround molding parts around door frame are applied to high grade automobiles, but there are great difficulties in their die development, construction and tryout because of several springback modes including vertical movement and twist during flange forming process of them. So it is very important to predict springback`s quantities of a surround molding part and, moreover, to compensate the die for them adequately, when they can`t be corrected by the restrike operation. This paper presents a case study based on the die design for a surround molding part made of stainless steel. The forming and springback predictions, carried out using PAMSTAMP 2G, are reported and compared with the measurement data of the prototype. The predicted springback results were acceptable, so the processes of compensating die using Automatic Die Compensation Module of PAMSTAMP 2G were performed iteratively until the tolerances between the designed shape and the simulation data were satisfied.
Characterization of High Temperature Mechanical Properties of Cast Stainless Steels for Exhaust Manifold
Lee, Kyu-Dong ; Ha, Tae-Kwon ; Jung, Jae-Young ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 217~222
DOI : 10.5228/KSPP.2009.18.3.217
Automobile industries have been focusing their efforts on the development of exhaust manifolds using high temperature stainless steels. Exhaust manifolds fabricated with stainless steels can be categorized into tubular and cast ones. The former is usually manufactured by forming and welding process and the latter by vacuum casting process. In the present study, high temperature mechanical properties of 5 austenitic and 4 ferritic stainless steels were investigated by performing a series of high temperature tensile and low cycle fatigue tests. One of the austenitic stainless steels was vacuum cast and the others sand cast. Fatigue life of ferritic stainless steels was higher than that of austenitic ones.
Effect of Stainless Steel Properties on Performance of Multi-layer Bellows
Suh, C.H. ; Oh, S.K. ; Jung, Y.C. ; Lee, R.G. ; Park, M.K. ; Kim, Y.S. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 223~228
DOI : 10.5228/KSPP.2009.18.3.223
Generally ferritic stainless steels are used for parts of exhaust system in commercial vehicle, because they have many advantages as low price and high corrosion resistant compared with austenitic stainless steels. Even though ferritic stainless steels have such various merits, austenitic stainless steels have been used to manufacture multi-layer bellows with complex geometry because of their high ductility. Recently, the mechanical properties of the ferritic stainless steels are getting improved and alternating austenitic stainless steel. In this paper, the possibility of mass production of multi-layer bellows made of ferritic stainless steel like MH1 and 443CT was studied. Tensile test, ridging test and corrosion test were carried out to observe material properties of STS304, MH1 and 443CT. Three types of prototype bellows were made using STS304, MH1 and 443CT stainless steels, and stiffness and fatigue tests were carried out to evaluate performance of the prototype bellows.
Quality Improvement for Crimping Process of Electrical Connector Using FEM Analysis
Yin, Z.H. ; Park, J.G. ; Choi, H.S. ; Kim, Y.S. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 229~235
DOI : 10.5228/KSPP.2009.18.3.229
This paper covers finite element simulations to evaluate the terminal crimping process of automobile electrical connector. Crimping is a classical technology process to ensure the electrical and the mechanical link between a wire and a terminal. Numerical modeling of the process is helpful to choose and to optimize the dimensions of the crimping part of the connector. In this paper, we discuss a 2D simulation of the crimping process, using explicit finite element methods (ABAQUS/Explicit) and we compare the results with experimental data from the industrial process of crimping (crimping height, crimping width and compressibility). The explicit method is preferred for the modeling of multi-contact problems, in spite of the quasi-static process of crimping. As compared with CAE analysis, a performance improvement makes certain of the truth of the matter.
Mechanical and Forming Characteristics of High-Strength Boron-Alloyed Steel with Hot Forming
Chae, M.S. ; Lee, G.D. ; Suh, Y.S. ; Lee, K.H. ; Kim, Y.S. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 236~244
DOI : 10.5228/KSPP.2009.18.3.236
In response to growing environmental and collision-safety concerns, the automotive industry has gradually used high-strength and ultla-high-strength steels to reduce the weight of automobiles. In order to overcome inherent process disadvantages of these materials such as poor formability and high springback at room temperature, hot forming has recently been developed and adopted to produce some important structural parts in automobiles. This method enables manufacturing of components with complex geometric shapes with minimal springback. In addition, a quenching process may enhance the material strength by more than two times. This paper investigates mechanical and forming characteristics of high-strength boron-alloyed steel with hot forming, in terms of hardness, microstructure, residual stress, and springback. In order to compare with experimental results, a finite element analysis of hot forming process coupled with phase transformation and heat transfer was carried out using DEFORM-3D V6.1 and also, to predict high temperature mechanical properties and flow curves for different phases, a material properties modeler, JMatPro was used.
Estimation of Design Variables for Improving the Bonding Force of Lid & Frame for Cellular Phone
Nam, K.J. ; Lee, J.M. ; Kim, B.M. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 245~250
DOI : 10.5228/KSPP.2009.18.3.245
A lid & frame used as the shield of electromagnetic waves in cellular phones are composed of frame, which is welded at their electric circuits, and lid, of which debonding and joining are available from the frame. Typical lid & frame were mechanically bonded by contact between the embossing of lid and the piercing of frame. Bonding force of this part has to allow us to detach the lid from frame for exchange or fix of the electric part and have to be high enough to protect the electric part from external impacts. This study is designed to estimate the effect of design variables of lid & frame on its debonding force. Estimations were performed by finite element method.
Effect of Thermal Oxidation Coating on the Hot Forging Process of High Strength Ti-6Al-4V Bolt
Kim, Jeoung-Han ; Lee, Chae-Hoon ; Hong, Jae-Keun ; Kim, Jae-Ho ; Yeom, Jong-Taek ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 251~255
DOI : 10.5228/KSPP.2009.18.3.251
Since fastener bolt for airplane require high specific strength and corrosion resistance, Ti-6Al-4V alloy is widely used. However, the Ti-6Al-4V bolt is generally manufactured by cutting and rolling because of their poor workability. The aim of present work is to develop hot forming technology for high strength Ti-6Al-4V. Various heat-treatments were applied to specimen in order to increase hot-workability and prevent galling with die. Multiple forging were simulated with FE code to determine optimum process parameters including specimen temperature, strain rate, local strain, and thermal shrinkage. Forged samples were heat-treated again to increase their mechanical properties.
A Study on Foaming Characteristics of Polyurethane Depending On Environmental Temperature and Blowing Agent Content
Kim, H.S. ; Youn, J.W. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 256~261
DOI : 10.5228/KSPP.2009.18.3.256
Polyurethane has been one of the most important materials for automobile elastic parts such as bumper, head rest, instrument panel and so on since it covers very wide range of mechanical characteristics with low production costs. The processing variables such as formulation of ingredients and mold temperature, mixing speed, etc. can affect the quality of produced polyurethane foams so that process conditions should be determined appropriately. In this study, foaming behaviors of semi-rigid polyurethane were investigated by conducting cup foam tests with two major processing variables such as environmental temperature and blowing agent content. In addition, it was verified that processing conditions of real practice can be determined effectively by considering foaming characteristics obtained by the cup foam tests.
Effect of Process Parameters on Forming Characteristics of Selective Laser Sintered Fe-Ni-Cr Powder
Joo, B.D. ; Jang, J.H. ; Yim, H.S. ; Son, Y.M. ; Moon, Y.H. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 262~267
DOI : 10.5228/KSPP.2009.18.3.262
Selective laser sintering is a kind of rapid prototyping process whereby a three-dimensional part is built layer wise by laser scanning the powder. This process is highly influenced by powder and laser parameters such as laser power, scan rate, fill spacing and layer thickness. Therefore a study on fabricating Fe-Ni-Cr powder by selective laser sintering has been performed. In this study, fabrication was performed by experimental facilities consisting of a 200W fiber laser which can be focused to 0.08mm and atmospheric chamber which can control atmospheric pressure with argon. With power increase or energy density decrease, line width was decreased and line surface quality was improved with energy density increase. Surface quality of quadrangle structure was improved with fill spacing optimization.
Analysis of the Evaporation Behavior of Resin Droplets in UV-Nanoimprint Process
Choi, D.S. ; Kim, K.D. ;
Transactions of Materials Processing, volume 18, issue 3, 2009, Pages 268~273
DOI : 10.5228/KSPP.2009.18.3.268
Ultraviolet nanoimprint lithography (UV-NIL), which is performed at a low pressure and at room temperature, is known as a low cost method for the fabrication of nano-scale patterns. In the patterning process, maintaining the uniformity of the residual layer is critical as the pattern transfer of features to the substrate must include the timed etch of the residual layer prior to the etching of the transfer layer. In pursuit of a thin and uniform residual layer thickness, the initial volume and the position of each droplet both need to be optimized. However, the monomer mixtures of resin had a tendency to evaporate. The evaporation rate depends on not only time, but also the initial volume of the monomer droplet. In order to decide the initial volume of each droplet, the accurate prediction of evaporation behavior is required. In this study, the theoretical model of the evaporation behavior of resin droplets was developed and compared with the available experimental data in the literature. It is confirmed that the evaporation rate of a droplet is not proportional to the area of its free surface, but to the length of its contact line. Finally, the parameter of the developed theoretical model was calculated by curve fitting to decide the initial volume of resin droplets.