• Journal of Environmental Health Sciences
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• v.30 no.4
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• pp.320-328
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• 2004

A number of health hazards are generated in welding processes. In this paper, the characteristics of fumes and some other hazardous agents in welding are reviewed. Fumes in welding are generated by complex mechanism like physical ejection of particles, oxidation-enhanced vaporization, vaporization-condensation-oxidation, and spatter contribution. Fume generation rates could be described as a power function in a given process. Most of fume constituents was originated from consumables rather than base metal. The mass distribution for the welding fumes is unimodal and very small to penetrate respiratory system. So, almost fractions of fumes are classified into the respirable particulate mass. Total chromium contents in FCAW were similar to those from SMAW whereas hexavalent chromium concentrations in fume were similar to those produced from MIG welding fume. Hexavalent chromium was mostly soluble which was similar to the characteristic solubility of fume hexavalent chromium from SMAW.

• Journal of Korean Society for Quality Management
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• v.21 no.2
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• pp.242-253
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• 1993

The interpretation of the reaction mechanism is significant to produce the high quality welds and understand the welding processes. This investigation is important for the design of welding consumables and the selection of welding process parameters to develop the high quality welds. The objective of this study is to investigate the effect of electrochemical reactions on the transfer of alloy elements between slag and weld metal during submerged arc welding During submerged arc welding weld metal composition is shown to be controlled by two reaction mechanisms in four reaction zones. The responsible reaction mechanisms are thermochemical and electrochemical reactions. The possible reaction sites are the melted electrode tip, the detached droplet, the hot weld pool immediately below the moving electrode, and the cooling and solidifying weld pool behind the moving electrode. The possible reactions in submerged arc welding at different zones of the process is schematically shown in Figure 1.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.4
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• pp.297-302
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• 2005

Chemical mechanical polishing(CMP) performances can be optimized by several process parameters such as equipment and consumables (pad, backing film and slurry). Pad properties are important in determining removal rate and planarization ability of a CMP process. It is investigated the performance of oxide CMP process using commercial silica slurry after the pad conditioning temperature was varied. Conditioning process with the high temperature made the slurry be unrestricted to flow and be hold, which made the removal rate of oxide film increase. The pad became softer and flexible as the conditioning temperature increases. Then the softer pad provided the better surface planarity of oxide film without defect.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.601-602
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• 2006

Chemical mechanical polishing (CMP) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, the cost of ownership and cost of consumables are relatively high because of expensive slurry. In this paper, we studied the mixed abrasive slurry(MAS). In order to save the costs of slurry, the original silica slurry was diluted by de-ionized water (DIW). And then, $ZrO_2$,$CeO_2$, and $MnO_2$ abrasives were added in the diluted slurry in order to promote the mechanical force of diluted slurry. We have also investigate the possibility of mixed abrasive slurry for the oxide CMP application.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.605-606
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• 2006

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40 %. So, we focused how to reduce the consumption of raw slurry. In this paper, $ZrO_2$,$CeO_2$, and $MnO_2$ abrasives were added de-ionized water (DIW) and pH control as a function of KOH contents. We have investigate the possibility of new abrasive for the oxide CMP application.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2233-2234
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• 2006

Chemical mechanical polishing (CMP) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, the cost of ownership and cost of consumables are relatively high because of expensive slurry. In this paper, we studied the mixed abrasive slurry(MAS). In order to save the costs of slurry, the original silica slurry was diluted by de-ionized water (DIW). And then, $ZrO_2$, $CeO_2$,and $MnO_2$ abrasives were added in the diluted slurry in order to promote the mechanical force of diluted slurry. We have also investigate the possibility of mixed abrasive slurry for the oxide CMP application.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2235-2236
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• 2006

Chemical mechanical polishing (CMP) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, the cost of ownership and cost of consumables are relatively high because of expensive slurry. In this paper, we studied the mixed abrasive slurry(MAS). In order to save the costs of slurry, the original silica slurry was diluted by de-ionized water (DIW). And then, $ZrO_2$, $CeO_2$,and $MnO_2$ abrasives were added in the diluted slurry in order to promote the mechanical force of diluted slurry. We have also investigate the possibility of mixed abrasive slurry for the oxide CMP application.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2237-2238
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• 2006

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40 %. So, we focused how to reduce the consumption of raw slurry. In this paper, $ZrO_2$, $CeO_2$, and $MnO_2$ abrasives were added de-ionized water (DIW) and pH control as a function of KOH contents. We have investigate the possibility of new abrasive for the oxide CMP application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.378-379
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• 2006

CMP(chemical mechanical polishing) process has been attracted as an essential technology of multi-level interconnection. However, the COO(cost of ownership) is very high, because of high consumable cost. Especially, among the consumables, slurry dominates more than 40 %. So, we focused how to reduce the consumption of raw slurry. In this paper, $ZrO_2$, $CeO_2$, and $MnO_2$ abrasives were added de-ionized water (DIW) and pH control as a function of KOH contents. We have investigate the possibility of new abrasive for the oxide CMP application.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.418-424
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• 2002

Korean Fusion Reactor(KSTAR) system consists of a vacuum vessel, in-vessel components, cryostat, thermal shield, super-conducting magnets and magnet supporting structures. These systems are in the final stage of engineering design with the involvement of industrial manufacturers. The overall configuration and the detailed dimensions of the KSTAR structure have been determined and the first stage of manufacturing is progressing now. In this study, the fabrication and assembly sequence were evaluated in viewpoint of high strengthening joints and very high accuracy. Especially for this purpose, the special cleaning process and welding process were proposed for high strengthening austenitic stainless steel which shall be used at cryogenic temperature. The draft procedure qualification data for welding process are presented with precise welding data including special narrow groove design. For the cooling line attachment on the surface of inside wall of magnet structure case, Induction brazing technology is introduced with some special jigging system and some consumables.