• 동력기계공학회지
• /
• 제7권2호
• /
• pp.61-65
• /
• 2003

Sheet metal forming process is a non-linearity problem which Is affected by various process variables, such as geometric shape of punch and die, frictional characteristic, etc.. Therefore, the knowledge of the influence of the process variables is needed in the design of sheet metal working processes. In this paper, deep drawing tests for blank holding force, punch speed and lubrication between sheet material and tool were carried out to investigate the influence upon sheet formability. Experimental results were discussed about the defects on the deformation behaviors during the forming process.

• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 2000년도 춘계공동학술대회 논문집
• /
• pp.625-629
• /
• 2000

The objective of ECMS(Environmentally Conscious Manufacturing Systems) is to consider environmental effects through the entire product life cycle from product development stage to design, manufacturing, supplying, using and disposing stage. Recently, environment-oriented recycling, reusing and manufacturing technologies have been researched actively in every engineering fields. In the field of chemical engineering, HHS (Health Hazard Scores) which classifies and analyzes hazardous materials in production processes has been presented. Metal cutting processes also have a lot of harmful factors, and especially hazardous components in cutting fluids have been known to have a bad effect on workers and working area. However, research works such as HHS have been little accomplished in metal cutting processes. In this research, a environmentally conscious machining process is presented by classifying hazardous components in cutting fluids, by using LCA(Life Cycle Assessments) and HHS method, and by evaluating environmental effects from cutting fluids.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2000년도 춘계학술대회
• /
• pp.225-239
• /
• 2000

The objective of ECMS(Environmentally Conscious Manufacturing Systems) is to consider environmental effects through the entire product life cycle from product development stage to design, manufacturing, supplying, using and disposing stage. Recently, environment-oriented recycling, reusing and manufacturing technologies have been researched actively in every engineering fields. In the field of chemical engineering, HHS(Health Hazard Scores) which classifies and analyzes hazardous materials in production processes has been presented. Metal cutting processes also have a lot of harmful factors, and especially hazardous components in cutting fluids have been known to have a bad effect on workers and working area. However, research works such as HHS have been little accomplished in metal cutting processes. In this research, a environmentally conscious machining process is presented by classifying hazardous components in cutting fluids, by using LCA(Life Cycle Assessments) and HHS method, and by evaluating environmental effects from cutting fluids.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 C
• /
• pp.1372-1374
• /
• 2001

This paper describes fabrication and characteristics of metal thin-film pressure sensor for working at high temperature. The proposed pressure sensor consists of a chrom thin-film, patterned on a Wheatstone bridge configuration, sputter-deposited onto thermally oxidized Si membranes with an aluminium interconnection layer. The fabricated pressure sensor presents a low temperature coefficient of resistance, high-sensitivity, low non-linearity and excellent temperature stability. The sensitivity is 1.097 $\sim$ 1.21 mV/V kgf/$cm^2$ in the temperature range of 25 $\sim$ $200^{\circ}C$ and the maximum non-linearity is 0.43 %FS.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.385-388
• /
• 2000

During the deep drawing process an initially flat blank is clamped between the die and the blank holder after which the punch moves down to deform the clamped blank into the desired shape. In general, sheet metal forming may involve stretching, drawing, bending or various combinations of those basic modes of deformation. The deformation problems of sheet metal working involve non-linearity in geometry and material. In this work, The punch load and thickness strain of electro-galvanized sheet steel (SECD) for elliptical deep drawing are examined under the various process conditions including, punch shape radius, die shape radius. The changes of punch load and thickness strain distribution of the deformed elliptical cup are affected by the size of each die shape radius.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1593-1596
• /
• 2003

Sheet metal forming process is a non-linearity problem which is affected by various process variables, such as geometric shape of punch and die, frictional characteristic, etc.. Therefore, the knowledge of the influence of the process variables is needed in the design of sheet metal working processes. In this paper, deep drawing tests for blank holding force, punch speed and lubrication between sheet material and tool were carried out to investigate the influence upon sheet formability. Experimental results were discussed about the defects on the deformation behaviors during the forming process.

• 한국기계가공학회지
• /
• 제3권4호
• /
• pp.43-49
• /
• 2004

The production parts have required multiple processes such as drawing, piercing, blanking and notching etc. are performed with a high production rates in progressive die. In order to prevent the defects of process result, the optimization of strip process layout design, die design, die making, and tryout etc. are needed. According to these factors of die development process, it has been required that the theory and practice of metal working process and its phenomena, die structure, machining conditions for die making, die materials, heat treatment of die components, processing know-how and so on. In this study, we designed and analyzed die components through the carrying out of upper relevant matters also simulated the strip process layout of multiple stage drawing by DEFORM. Especially the result of tryout and its analysis became to the feature of this study with a system of PDDC(Progressive Die design by computer).

• Toxicological Research
• /
• 제33권2호
• /
• pp.135-140
• /
• 2017

The cobalt (Co(II)) ion is a main component of alloys and considered to be carcinogenic, especially due to the carcinogenic and toxicological effects in the aquatic environment. The toxic trace of the Co(II) detection was conducted using the infrared photodiode electrode (IPDE) using a working electrode, via the cyclic and square-wave anodic stripping voltammetry. The results indicated a sensitive oxidation peak current of Co(II) on the IPDE. Under the optimal conditions, the common-type glassy carbon, the metal platinum, the carbon paste, and the carbon fiber microelectrode were compared with the IPDE in the electrolyte using the standard Co(II). The IPDE was found to be far superior to the others.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 추계학술대회 논문집
• /
• pp.151-154
• /
• 2002

In this paper a mathematical model, the results of computer simulation and exprimental investigations of electrochemical machining with a too-electrode are presented. The experimental investigations were carried out in order to evaluate the influence of working voltage, initial interelectrode gap size, and metal remove rate. Accuracy of computer simulation evaluated by differences between results of experimental test and computer simulation depends on electrochemical machining coefficient, total overpotential of electrode process, current density, electrical conductivity of electrolyte, and etc. Metal removal rate would be predicted by the simulation of ECM process.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 1996년도 제6회 학술강연회논문집
• /
• pp.197-205
• /
• 1996

A combined extrusion process studied here consists of forward and backward extrusion, and it is formed in single operation. The metal flow involved in the operation has appeared to be difficult to analyze accurately because of mixed directions of the flow. In this study, conventional two operations of a forward and a backward extrusions is transformed into one operation of mixed extrusion. A process designed by an industry expert is simulated by the rigid-plastic finite element method to investigate the metal flow and defects. In addition to the FEM simulation, experimental analysis has been carried out to confirm the design in industry, which includes material characterization, preliminary expriment, and whole experimental forming operation. The experimental results show that warm forming of extrusion is more desirable than cold working and hot forming in view of grain growth. Also two conditions of lubrication between workpiece and die has been investigated.