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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 11, Issue 8 - Dec 2002
Volume 11, Issue 7 - Nov 2002
Volume 11, Issue 6 - Oct 2002
Volume 11, Issue 5 - Sep 2002
Volume 11, Issue 4 - Aug 2002
Volume 11, Issue 3 - Apr 2002
Volume 11, Issue 2 - Apr 2002
Volume 11, Issue 1 - Feb 2002
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Micromachining Technologies and its application to MEMS Optical Switch
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 103~107
DOI : 10.5228/KSPP.2002.11.2.103
With the great demand for WDM (Wavelength Division Multiplexing) optical communications, optical switches are expected to become one of the dominant components in future networks. Conventional mechanical switches suffer from poor reliability and large size; however, many micromachined optical switches with moving mirrors have been proposed for high scale OXC (Optical Crossconnect) or ADM (Add/Drop Multiplex) because of the low power consumption and high reliability of these switches. In this paper, we introduce the technological trends of optical switches using MEMS, related micromachining technologies and their characteristics.
Applications of MEMS Technology on Medicine & Biology
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 108~113
DOI : 10.5228/KSPP.2002.11.2.108
The application fields of medicine and biology are spotlighted because of the increasing concentration of health and the abundance of life. MEMS is very good solution in this fields for the concept of point of care which makes systems more useful and spread wide. This paper shows the major fabrication schemes and application fields of microelectromechanical system specially in medicine and biology fields.
Metal Viscosity and Semisolid Forming Technology
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 114~122
DOI : 10.5228/KSPP.2002.11.2.114
Research Trends of Rheology Forming and Their Solutions to Mass Production
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 123~131
DOI : 10.5228/KSPP.2002.11.2.123
The rheology process is net shape manufaturing technology to high of automobile part and improve the mechanical properties. For the rheology forming process, Phase and globular microstructure are very important. The equipments to make a rheology alloys with slurry statement have been introduced. Therefore, the Problems to Produce a rheology alloyas with continuous process had also been investigated to make Production in industries. The validity of the introduced rheology Process is investigated by comparing the reported thixoforming results. Therefore, the many advantage of rheology process to be reduced the reheating Process and billet fabrication method has been expressed in terms of mass production, in the future.
A Study on the Characteristics of the Precision Blanking of Lead Frame (II): Determination of Optimal Process Condition
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 132~137
DOI : 10.5228/KSPP.2002.11.2.132
Using the Taguchi method, optimum process condition of lead frame blanking has been determined in the point of view of shape of blanked profile. As the main process parameters, clearance, strip holding pressure and bridge width are selected. According to the orthogonal array table, three levels of experiment have been carried out for each factor. The optimal blanking condition is analyzed with the SN ratio. It has been verified that the optimal Process condition can be determined with a combination of basic blanking experiment and experiment design method. Both the effect of each factor and gain can be judged in the quantitative manner from the analysis of SN ratio.
Elasto-plastic Finite Element Analysis for the Parametric Process Design of the Tension Leveller(1) -Unit Model Analysis
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 138~146
DOI : 10.5228/KSPP.2002.11.2.138
This paper is concerned with the simulation-based process design method involved non-steady state problem of tension levelling considering the elasto-plastic hardening behavior of a metallic strip by a commercial code ABAQUS/Standard. The tension levelling process is peformed to elongate the strip plastically in combination of tensile and bending strain by a controlled manner so that all longitudinal fibers in the strip have an approximately equal amount of length and undesirable strip shapes are corrected to the flat share. Objectives of this paper are the development of a general method for the design of a tension leveller by a finite element method and parameter studies for the deisgn variables such as the applied tension, the roll intermash includes the determination of the steady state using the simple unit of the tension levelling line and the effect of the finite element mesh size on the amount and distribution of the strain calculated. The analysis provides the information about the intermesh effect on the amount and final shapes of the strip and distribution of the strain in order to determine the amount elongation for correction of the irregular share.
Plasto-plastic Finite Element Analysis for the Parametric Process Design of the Tension Leveller(2) -Full Set Analysis
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 147~154
DOI : 10.5228/KSPP.2002.11.2.147
The tension levelling Process is Performed to elongate the strip plastically In combination of tensile and bending strain so that all longitudinal fibers In the strip have an approximately equal amount ofn length and undesirable strip shapes are corrected to the flat shape. Thus paper is concerned with a simulation of the tension levelling process based on the analysis of tile unit model for the tension leveller. Analysis technique such as the sequential analysis of the unit model is suggested and verified with the assembly analysis of the unit model for the effective arts economic analysis of the full set of the tension leveller. Analysis of the full tension levelling Process using sequential unit models Is carried out for steel strips with the shape defect and provides the effect of the intermesh and optimum amount of the intermesh in tension levelling process.
The Effect of globule size on the Mechanical Properties in Reheating Process of Aluminium Alloys
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 155~164
DOI : 10.5228/KSPP.2002.11.2.155
One of the important steps on semi-solid forming Is the reheating process of raw materials to the semi-solid state. This Process is not only necessary to achieve the required SSM billet state, but also to contro1 the microstructure of the billet. In reheating process, the globule size is determined by the holding time of last heating stage. Therefore, some experiments to investigate the relationship between the mechanical properties and the holding time in the last heating stage was performed. The alloys used in this experiment were 357, 319 and A390 alloys. The experiments of reheating were performed by using an Induction heating system with the capacity of 50kw. This paper shows the evolution of the microstructure according to the holding time of last reheating stage. Furthermore, to evaluate the effect of globule size controlled by holding time in last heating stage uniaxial tension test was performed. The strain-stress curves were plotted according to the holding time.
The Optimal Design of Preform in 3-D Forging by using Electric Field Theory
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 165~170
DOI : 10.5228/KSPP.2002.11.2.165
The preform design of forging processes plays a key role in improving product qualities, such as defect prevention, dimensional accuracy and mechanical strengths. In the industry, preforms are generally designed by the iterative trial-and-error approach, but it results in significant tooling cost and time. It is thus necessary to minimize lead-time and human intervention through an effective preform design method. In this paper, the equi-potential lines designed in the electric field are introduced to find the preform shape, and then the optimization process is used to choose the equi-potential lines that will keep the die wear to a minimum Because, in the forging process, the die wear is a function of various important factors, such as forming stress and strain, microstructure and mechanical properties of a Product.
A Study on the Experimental and Theoretical Analysis About the Elastic Deflections of Die for Cold Forging
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 171~178
DOI : 10.5228/KSPP.2002.11.2.171
The elastic deflections of the cold forging die influence the dimensional accuracy of forged parts. The die dimension is continuously changed during the loading, unloading, and ejecting stage. In this paper, we evaluated the elastic deflections of cold forging die during the loading, unloding and ejecting stage with experimental and FEM analysis. Uni-axial strain gages are used to measure elastic strain of die during each forging stage. Strain gages are attached un the upper surface of die. A commercial F.E.M. code, DEFORM
is used to predict the elastic strains of die, to be compared those by experiments. Two modelling approaches are used to define the reasonable analysis method. The first of the two modelling approaches is to regard the die as rigid body over forging cycle. And then, the die stress is analyzed by loading the die with pressure from the deformed part. The other is to regard the die as elastic body from forging cycle. The elastic strain of tool is calculated and the tool is elastically deformed at each strep. The calculated results under the elastic die assumption are well agreed wish experimental data using the strain gages.
3-D Analysis of Hot Forging Processes using the Mesh Compression Method
Transactions of Materials Processing, volume 11, issue 2, 2002, Pages 179~186
DOI : 10.5228/KSPP.2002.11.2.179
In the finite element analysis of metal forming Processes using general Lagrangian formulation, element nodes in the mesh move and elements are distorted as the material is deformed. The excessive degeneracy of mesh interrupts finite element analysis and thus increases the error of plastic deformation energy, In this study, a remeshing scheme using so-called mesh compression method is proposed to effectively analyze the flash which is generated usually in hot forging processes. In order to verify the effectiveness of the method, several examples are tested in two-dimensional and three-dimensional problems.