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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of Materials Processing
Journal Basic Information
Journal DOI :
The Korean Society for Technology of Plasticity
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Volume & Issues
Volume 16, Issue 8 - Dec 2007
Volume 16, Issue 7 - Nov 2007
Volume 16, Issue 6 - Oct 2007
Volume 16, Issue 5 - Aug 2007
Volume 16, Issue 4 - Jul 2007
Volume 16, Issue 3 - Jun 2007
Volume 16, Issue 2 - Apr 2007
Volume 16, Issue 1 - Feb 2007
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New Riveting Technology
Kato, T. ; Mori, K. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 341~347
DOI : 10.5228/KSPP.2007.16.5.341
Visualization of High Speed fracture Behavior in Y-TZP by using Mechano-luminescence
Kim, J.S. ; Sohn, K.S. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 348~353
DOI : 10.5228/KSPP.2007.16.5.348
The propagation of a macro-scale crack and the accompanying transformation zone around it was visualized in an Y-TZP ceramic using a mechano-luminescence (ML) technique. The technique allows realistic fractures that take place catastrophically in actual applications to be realistically stimulated. Unlike conventional quasi-static R-curves, the ML technique on a relatively fast time frame permitted a so-called quasi-dynamic R-curve in the crack speed range from 50 to 140 m/sec. to be measured. Effective toughening then commenced and the applied stress intensity factor increased to 27
. The transformation zone height obtained from the ML observations was in good agreement with that predicted by the Marshall model, and coincided with previously observed results for quasi-static conditions by Raman spectorscopy and x-ray analysis.
Evaluation of Mechanical Property and Microstructure of Forged and T6-treated 6061 Aluminum Alloy Wheel
Lee, J.H. ; Jeong, H.S. ; Yeom, J.T. ; Kim, J.H. ; Park, N.K. ; Lee, Y.T. ; Lee, D.G. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 354~359
DOI : 10.5228/KSPP.2007.16.5.354
Effects of forging and mechanical properties of 6061 aluminum alloy wheel for automobiles were investigated in the present study. Microstructural and tensile characteristics of automobile wheel after hot forging process using dynamic screw press were analyzed to evaluate effect of metal flow on mechanical properties. The results showed advanced mechanical properties of 6061 alloy wheel because of
precipitation by T6, elongated grain by forging, and work hardening by dense metal flow, etc. Hot compression tests were conducted in order to characterize high temperature compression deformation behaviors and microstructural variation in the range of
, in the strain rate range of
. As strain rate increased, maximum compression stress increased but it was shown the reverse linear relation between temperature and maximum stress irrelevant to strain rate variation. On the other hand, temperature and yield stress didn't have any linear relation and its relation showed big deviation by a function of strain rate and test temperature.
Nanocrystallization of Metallic Powders during High Pressure Torsion Processing
Yoon, Seung-Chae ; Kwak, Eun-Jeong ; Kim, Taek-Soo ; Hong, Sun-Ig ; Kim, Hyoung-Seop ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 360~363
DOI : 10.5228/KSPP.2007.16.5.360
Microstructure and microhardness of metallic powders of pure copper were studied after high pressure torsion(HPT) processing with 10 turns of die rotation and high pressure of 6 GPa. The grain size of copper decreases drastically after HPT and reaches nanometer size ranges. During HPT, the hardness of consolidates of copper powders increases with increasing the temperature of HPT processing. Examinations of the fracture surfaces indicated evidence of ductile fracture. The results proved that HPT of copper powders has a beneficial effect for homogeneous deformation with reducing grain size.
Experiments for Forming Limit Diagram and Springback Characteristics of AZ31B Magnesium Alloy Sheet at Elevated Temperature
Kim, H.Y. ; Choi, S.C. ; Lee, H.S. ; Kim, H.J. ; Lee, K.T. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 364~369
DOI : 10.5228/KSPP.2007.16.5.364
The effect of temperature on the forming limit diagram was investigated for AZ31B magnesium alloy sheet through the limit dome height test in the range from room temperature to
. The formability of AZ31B sheet was improved significantly according to the increasing temperature. Also we studied the springback characteristics through the 2D draw bending test with different blank holding forces at elevated temperatures. Springback quantity was considerably reduced as temperature went up. The blank holding force in the range used, however, had little influence on springback. Experimental results obtained in this study may provide a material database for AZ31B sheet.
Investigation for Impact Stability of the Motorcycle Helmet by Using Finite Element Method
Yu, B.M. ; Song, J.S. ; Kim, D. ; Lee, S.K. ; Kim, Y.H. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 370~374
DOI : 10.5228/KSPP.2007.16.5.370
A motorcycle helmet is very essential to protect the head of driver and it is directly connected to driver's life. Prior to producing the helmet, it has to be passed the process of impact test to evaluate its safety. This test evaluates peak acceleration and head injury criteria (H.I.C.). This paper simulates the impact test with finite element method to find the behavior of helmet during the test. Also, the effect of impact sites on the helmet was evaluated to improve the thickness distribution of the helmet.
Development of New Bimetal Material for Home Appliances by Using the Rolling Process
Park, S.S. ; Lee, J.H. ; Bae, D.H. ; Bae, D.S. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 375~380
DOI : 10.5228/KSPP.2007.16.5.375
The bimetals of home appliances are mainly manufactured by cladding process and these are almost consisted with Cu alloy and Ni alloy. But it is very difficult to clad these alloys, because the brittle
oxide film formed easily on Cu alloy surface during cladding process. Clad rolling and heat treatment processes were applied for the development of bimetals by using the Ni alloy and the 3 types of Cu alloys. Optical microstructure, micro-hardness, specific resistance, and deflection and line profile of newly processed bimetals specimens were observed and measured in this paper. Inter-diffusion was observed between Cu and Ni element in the interface of heat treated Cu alloy and Ni alloy clad material. The C1220 and Invar36 clad material showed the best property of deflection among the 3 kind of clad materials.
Effects of Blank Holding Force on the Friction Behavior in Sheet Metal Forming
Shim, J.W. ; Keum, Y.T. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 381~385
DOI : 10.5228/KSPP.2007.16.5.381
In order to examine the effect of the blank holding force on the friction behavior in the sheet metal forming, a sheet metal friction tester is designed and manufactured, which can measure friction forces in various forming conditions such as lubrication, die roughness, drawing speed, radius of die corner, blank holding force, etc., and the friction tests are performed, in which friction coefficients in various blank holding forces and pulling speeds are calculated using Coulomb's friction law. The friction test reveals that friction coefficient decreases as the blank holding force, the drawing speed and lubricant viscosity increase together or individually.
Microstructure Control of Cu-Ni-Zr-Ti Metallic Glass Composites by Multi-Pass Extrusion Process
Kim, Taek-Soo ; Lee, Jin-Kyu ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 386~390
DOI : 10.5228/KSPP.2007.16.5.386
In order to, simultaneously, synthesize and control the size of microstructure of amorphous/crystalline composites, a repeated extrusion process was performed using the gas atomized
metallic glass powders and the crystalline brasses. The size of microstructure in the resultant composites was varied depending on the pass of extrusion as well as on the area reduction ratio. The microstructure could be estimated using an equation of
, where R is reduction ratio and
is the resultant radius of the extruded bar after n pass. Theory of microstructural refinement as well as the relationship between the resultant microstructures and mechanical properties was discussed.
Characteristics on the Hot Extrusion of Semi-Solid Al-Zn-Mg Alloy
Cho, Kuk-Rae ; Yeom, Jong-Taek ; Shim, Sung-Yong ; Lim, Su-Gun ; Park, Nho-Kwang ; Kim, Jeoung-Han ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 391~395
DOI : 10.5228/KSPP.2007.16.5.391
Semi-solid Al-Zn-Mg alloys were produced by using a cooling plate method in order to investigate the extrudability. Al melt was poured on cooling plate which was adjusted at
with respect to the horizontal plane, and the melt was cooled by water circulation underneath. Obtained Semi-solid feedstock has globular microstructure but also contains considerable amount of gas pore. Due to the pore, tensile elongation of the semi-solid feedstock was very low and it doesn't show yield point phenomenon. Isothermal hot extrusion was carried out using at
with a ram speed of 1mm/sec and an extrusion ratio of 25:1. The extruded bar show noticeably improved tensile ductility and strength because pore volume fraction decreased from 5% to 0.8% after extrusion. Mechanical properties of the semi-solid extruded bar were compared with that of commercial casting alloy.
Influence of Laminating and Sintering Condition on Permittivity and Shrinkage During LTCC Process
Jeong, M.S. ; Hwang, S.H. ; Chung, H.W. ; Rhim, S.H. ; Oh, S.I. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 396~400
DOI : 10.5228/KSPP.2007.16.5.396
LTCC(Low Temperature Co-fired Ceramic) which offers a good performance to produce multilayer structures with electronic circuits and components has emerged as an attractive technology in the electronic packaging industry. In LTCC module fabrication process, the lamination and the sintering are very important processes and affect the electrical characteristics of the final products because the processes change the permittivity of ceramics and the dimension of the circuit patterns which have influences on electronic properties. This paper discusses the influence of lamination pressure and sintering temperature on the permittivity and the dimensional change of LTCC products. In the present investigation, it is shown that the permittivity increases along with increasing of the lamination pressure and the sintering temperature.
Forming Analysis for Warm Deep Drawing Process of Magnesium Alloy Sheet
Lee, M.H. ; Kim, H.Y. ; Kim, H.J. ; Kim, H.K. ; Oh, S.I. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 401~405
DOI : 10.5228/KSPP.2007.16.5.401
Due to the low densities and high specific strength and stiffness, magnesium alloy sheets are very attractive lightweight materials for automotive and electrical products. However, the magnesium alloy sheets should be usually formed at elevated temperature because of their poor formability at room temperature. For the use of the magnesium alloy sheets for an industrial, their mechanical properties at elevated temperature and appropriate forming process conditions have to be developed. In this study, non-isothermal simulation of a square cup drawing of magnesium alloy sheets have been conducted to evaluate a proper forming process conditions such as the tool temperature, the tool shoulder radius, friction between the blank and the tools. According to this study, appropriate forming process conditions of square cup drawing at elevated temperature from magnesium alloy sheets are suggested.
Effects of the Processing Temperature and the Number of Passes of Equal Channel Angular Pressing on the Microstructure and Hardness of IF Steel
Yoon, S.C. ; Ryu, W.S. ; Baik, S.C. ; Kim, H.S. ;
Transactions of Materials Processing, volume 16, issue 5, 2007, Pages 406~411
DOI : 10.5228/KSPP.2007.16.5.406
The microstructure and the hardness of interstitial free steel processed by equal channel angular pressing (ECAP) was investigated experimentally. ECAP processing of route A and route C was compared with regard to grain refinement by transmission electron micrographs. Micro hardness evolution was correlated with the gram structure produced by ECAP. Especially, the effects of the ECAP processing temperature and the number of processing passes were discussed in terms of grain refinement.