The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Yool Kwon Oh - One of the best experts on this subject based on the ideXlab platform.
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A Study on Solidification Characteristics of Aluminum Alloy Casting Material by Pre-heated Temperature Conditions
2020Co-Authors: Cheonhan Yoon, Hee Sung Yoon, Yool Kwon OhAbstract:In this study, the solidification characteristics inside the AC7A Casting Material was analyzed using the numerical analysis method and was verified using the experimental method by the pre-heated temperature conditions of metal Casting device. For the numerical analysis, "COMSOL Multiphysics", the commercial code based on the finite element analysis(FEA), was used in order to predict the thermal deformation of the AC7A Casting Material including temperature, displacement and stress distribution. Also, in order to verify the results calculated by the numerical analysis, the experiment for temperature measurement inside the AC7A Casting Material was performed using the K-type thermocouple under the same condition of numerical analysis method. In the numerical results, thermal deformation inside AC7A Casting Material was well-suited for manufacturing products when the pre-heated temperatures of the metal Casting device was . When the results of the temperature distribution were experimentally measured and were compared with those of the numerical result, it appeared that there was some temperature difference because of the latent heat by phase change heat transfer. However, the result of cooling temperature and patterns were almost similar except for the latent heat interval. The solidification characteristics was closely related to the temperature difference between the surface and inside of the Casting.
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Thermal deformation of aluminum alloy Casting Materials for tire mold by numerical analysis
Transactions of Nonferrous Metals Society of China, 2012Co-Authors: Hee Sung Yoon, Je-se Choi, Yool Kwon OhAbstract:Thermal deformation of aluminum alloy Casting Materials for manufacturing the tire mold was numerically investigated. The AC7A and AC4C Casting Material was selected as Casting Material and the metal Casting device was used in order to manufacture the mold product of automobile tire in the actual industrial field. The temperature distribution and the cooling time of Casting Materials were numerically calculated by finite element analysis (FEA). Also, the thermal deformation such as displacement and stress distribution was calculated from the temperature results. The thermal deformation was closely related to the temperature difference between the surface and inside of the Casting. The numerical analysis results reveal that the thermal deformation of AC7A Casting Material is higher than that of AC4C Casting Material. Also, the thermal deformation results at the central part are larger than that on the side of Casting because of the shrinkage caused by the cooling speed difference.
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NUMERICAL AND EXPERIMENTAL STUDY ON THERMAL DEFORMATION OF AC7A AND AC4C Casting Material
2012Co-Authors: Hee Sung Yoon, Ho Dong Yang, Yool Kwon OhAbstract:The present study was numerically and experimentally investigated on thermal deformation of AC7A and AC4C aluminum alloy used as a Casting Material for manufacturing automobile tire mold. In this study, temperature distributions of AC7A and AC4C Casting Material were numerically calculated by finite element analysis (FEA). In order to compare and verify results calculated by numerical analysis, the experiment was carried out on the same condition of numerical analysis. The temperature distribution numerical analysis result revealed that the cooling patterns were predicted almost similar results during cooling process of two Casting Material. Also, the thermal deformation was calculated from the temperature distribution results. The thermal deformation was closely related to the temperature difference between the surface and inside of the Casting.
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A Study on Cooling Characteristics of AC4C and AC7A Casting Material for Manufacturing Tire Mold
Advanced Materials Research, 2011Co-Authors: Hee Sung Yoon, Ho Dong Yang, Yool Kwon OhAbstract:This study investigated on the cooling characteristics of AC4C aluminum alloy and AC7A aluminum alloy used as a Casting Material for manufacturing automobile tire mold by experiment. The metal mold device by gravity Casting method was manufactured. AC4C Casting Material and AC7A Casting Material were heated in smelting furnace at about 650°C and 670°C, and then they injected into the metal mold device when the melting process was completely finished, respectively. When the melted Casting Material was completely injected into the metal mold device, the temperature inside the Casting was measured by 9 measurement points. Also, when the temperature inside the Casting was measured approximately 500°C during the cooling process, the Casting is separated to metal mold device and carried out cooling at normal temperature. The separating time from metal mold device of AC4C Casting Material and AC7A Casting Material have been taken 25 minutes and 15 minutes, respectively. The final cooling time of AC4C Casting Material and AC7A Casting Material have been taken 400 minutes and 380 minutes, respectively. Accordingly, AC7A Casting Material is able to improve on productivity than AC4C Casting Material because production time was decreasing.
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A STUDY ON THERMAL DEFORMATION OF AC4C ALUMINUM ALLOY Casting Material FOR TIRE MOLD IN METAL Casting METHOD
International Journal of Modern Physics B, 2010Co-Authors: Yool Kwon Oh, Hee Sung Yoon, Ho Dong YangAbstract:This study investigated on thermal deformation of AC4C aluminum alloy Casting Material for tire mold built in metal Casting method. In this study, temperature, displacement and stress distributions of AC4C Casting Material occurred inside the mold were numerically calculated by finite element analysis (FEA). Also, temperature profiles of AC4C were experimentally measured to investigate the temperature characteristics during the solidification process in metal Casting device. The result of this study revealed that the numerical result of temperature profiles predicted a rapid cooling from initial state to about 25 minutes, but the experimental result of it uniformly occurred from initial state to about 15 minutes by the phase change. However, the cooling patterns of two cases were almost similar results in the whole cooling process. Also, thermal deformation was generated by the difference of cooling temperature between the surface and inside of the Casting from the results of displacement and stress distribution predicted by FEA.
Vincenzo Palleschi - One of the best experts on this subject based on the ideXlab platform.
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Quantitative analysis of metals in waste foundry sands by calibration free-laser induced breakdown spectroscopy
Spectrochimica Acta - Part B Atomic Spectroscopy, 2017Co-Authors: D. M. Díaz Pace, R. E. Miguel, H. O. Di Rocco, F. Anabitarte García, L. Pardini, Gloria Lorenzetti, Stefano Legnaioli, Vincenzo PalleschiAbstract:Laser-induced breakdown spectroscopy (LIBS) was applied for quantitative analysis of the elemental composition of waste molding and core sands produced from industry as part of the Casting process. To perform the analysis, waste foundry sands (WFS) were collected from metalCasting foundries and prepared in the form of solid pellets with the addition of polyvinyl alcohol as binder. The measurements were carried out using the Mobile double pulse instrument for LIBS analysis (Modì). The spectral analysis was carried out with the calibration-free approach (CF-LIBS). Metal elements commonly found in WFS including Al, Ba, Fe, Li, Mg, Mn, Pb, Ti, Zr, and Zn, were detected and quantified. The metal concentrations for WFS were compared with virgin sand to assess the influence of the Casting Material as well as the binders used in the foundries to reclaim the sands. The results demonstrated the feasibility of LIBS method as an alternative or complementary technique for the chemical characterization of WFS.
Hee Sung Yoon - One of the best experts on this subject based on the ideXlab platform.
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A Study on Solidification Characteristics of Aluminum Alloy Casting Material by Pre-heated Temperature Conditions
2020Co-Authors: Cheonhan Yoon, Hee Sung Yoon, Yool Kwon OhAbstract:In this study, the solidification characteristics inside the AC7A Casting Material was analyzed using the numerical analysis method and was verified using the experimental method by the pre-heated temperature conditions of metal Casting device. For the numerical analysis, "COMSOL Multiphysics", the commercial code based on the finite element analysis(FEA), was used in order to predict the thermal deformation of the AC7A Casting Material including temperature, displacement and stress distribution. Also, in order to verify the results calculated by the numerical analysis, the experiment for temperature measurement inside the AC7A Casting Material was performed using the K-type thermocouple under the same condition of numerical analysis method. In the numerical results, thermal deformation inside AC7A Casting Material was well-suited for manufacturing products when the pre-heated temperatures of the metal Casting device was . When the results of the temperature distribution were experimentally measured and were compared with those of the numerical result, it appeared that there was some temperature difference because of the latent heat by phase change heat transfer. However, the result of cooling temperature and patterns were almost similar except for the latent heat interval. The solidification characteristics was closely related to the temperature difference between the surface and inside of the Casting.
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Thermal deformation of aluminum alloy Casting Materials for tire mold by numerical analysis
Transactions of Nonferrous Metals Society of China, 2012Co-Authors: Hee Sung Yoon, Je-se Choi, Yool Kwon OhAbstract:Thermal deformation of aluminum alloy Casting Materials for manufacturing the tire mold was numerically investigated. The AC7A and AC4C Casting Material was selected as Casting Material and the metal Casting device was used in order to manufacture the mold product of automobile tire in the actual industrial field. The temperature distribution and the cooling time of Casting Materials were numerically calculated by finite element analysis (FEA). Also, the thermal deformation such as displacement and stress distribution was calculated from the temperature results. The thermal deformation was closely related to the temperature difference between the surface and inside of the Casting. The numerical analysis results reveal that the thermal deformation of AC7A Casting Material is higher than that of AC4C Casting Material. Also, the thermal deformation results at the central part are larger than that on the side of Casting because of the shrinkage caused by the cooling speed difference.
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NUMERICAL AND EXPERIMENTAL STUDY ON THERMAL DEFORMATION OF AC7A AND AC4C Casting Material
2012Co-Authors: Hee Sung Yoon, Ho Dong Yang, Yool Kwon OhAbstract:The present study was numerically and experimentally investigated on thermal deformation of AC7A and AC4C aluminum alloy used as a Casting Material for manufacturing automobile tire mold. In this study, temperature distributions of AC7A and AC4C Casting Material were numerically calculated by finite element analysis (FEA). In order to compare and verify results calculated by numerical analysis, the experiment was carried out on the same condition of numerical analysis. The temperature distribution numerical analysis result revealed that the cooling patterns were predicted almost similar results during cooling process of two Casting Material. Also, the thermal deformation was calculated from the temperature distribution results. The thermal deformation was closely related to the temperature difference between the surface and inside of the Casting.
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A Study on Cooling Characteristics of AC4C and AC7A Casting Material for Manufacturing Tire Mold
Advanced Materials Research, 2011Co-Authors: Hee Sung Yoon, Ho Dong Yang, Yool Kwon OhAbstract:This study investigated on the cooling characteristics of AC4C aluminum alloy and AC7A aluminum alloy used as a Casting Material for manufacturing automobile tire mold by experiment. The metal mold device by gravity Casting method was manufactured. AC4C Casting Material and AC7A Casting Material were heated in smelting furnace at about 650°C and 670°C, and then they injected into the metal mold device when the melting process was completely finished, respectively. When the melted Casting Material was completely injected into the metal mold device, the temperature inside the Casting was measured by 9 measurement points. Also, when the temperature inside the Casting was measured approximately 500°C during the cooling process, the Casting is separated to metal mold device and carried out cooling at normal temperature. The separating time from metal mold device of AC4C Casting Material and AC7A Casting Material have been taken 25 minutes and 15 minutes, respectively. The final cooling time of AC4C Casting Material and AC7A Casting Material have been taken 400 minutes and 380 minutes, respectively. Accordingly, AC7A Casting Material is able to improve on productivity than AC4C Casting Material because production time was decreasing.
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A STUDY ON THERMAL DEFORMATION OF AC4C ALUMINUM ALLOY Casting Material FOR TIRE MOLD IN METAL Casting METHOD
International Journal of Modern Physics B, 2010Co-Authors: Yool Kwon Oh, Hee Sung Yoon, Ho Dong YangAbstract:This study investigated on thermal deformation of AC4C aluminum alloy Casting Material for tire mold built in metal Casting method. In this study, temperature, displacement and stress distributions of AC4C Casting Material occurred inside the mold were numerically calculated by finite element analysis (FEA). Also, temperature profiles of AC4C were experimentally measured to investigate the temperature characteristics during the solidification process in metal Casting device. The result of this study revealed that the numerical result of temperature profiles predicted a rapid cooling from initial state to about 25 minutes, but the experimental result of it uniformly occurred from initial state to about 15 minutes by the phase change. However, the cooling patterns of two cases were almost similar results in the whole cooling process. Also, thermal deformation was generated by the difference of cooling temperature between the surface and inside of the Casting from the results of displacement and stress distribution predicted by FEA.
Matthew R. I. Meng - One of the best experts on this subject based on the ideXlab platform.
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Commonly used adjuvants (liquid soap, foam sanitizer, or ultrasound gel) do not improve strength or curing time of fiberglass cast Material
Journal of Orthopaedic Surgery and Research, 2019Co-Authors: Matthew R. I. Meng, Joseph W. Elphingstone, Margaret A. Sinkler, Bruce M. Byrd, Meghan E. Mcgee-lawrenceAbstract:Background Bone fractures are one of the most common injuries in the USA. Fiberglass tape is a commonly used Casting Material, and many medical professionals apply adjuvants including liquid hand soap, foam sanitizers, and ultrasound gel in the hopes of improving outcomes relating to ease of molding and eventual strength, lamination, and smoothness of cast Material. However, the efficacy of these agents to improve fiberglass cast mechanics has not been scientifically evaluated. The purpose of this study was to assess the mechanical effects of commonly used adjuvants on fiberglass cast Materials. Methods Studies compared regularly shaped samples of water-activated, untreated fiberglass tape (Ossur Techform Premium) to water-activated fiberglass tape treated with one of three commonly used adjuvants (liquid soap, foam hand sanitizer, or ultrasound gel) during lamination. Material stiffness, yield stress, and ultimate load were measured by 3-point bending. Results These studies demonstrated that that liquid soap and ultrasound gel did not affect fiberglass tape mechanical properties, but alcohol-based foam sanitizer significantly reduced stiffness (− 32.8%), yield stress (− 33.6%), and ultimate load (− 31.0%) of the cast Material as compared to the control group. Regression slopes were not significantly different between groups, suggesting that no adjuvants improved Material curing time. Conclusions These data suggest that the application of adjuvants is not beneficial and potentially harmful to fiberglass cast behavior. Despite the widespread practice of adjuvant application by medical professionals during Casting, results from the current study suggest that use of these agents for structural enhancement of fiberglass casts is not beneficial and should largely be discouraged.
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commonly used adjuvants liquid soap foam sanitizer or ultrasound gel do not improve strength or curing time of fiberglass cast Material
Journal of Orthopaedic Surgery and Research, 2019Co-Authors: Matthew R. I. Meng, Joseph W. Elphingstone, Margaret A. Sinkler, Bruce M. Byrd, Meghan E McgeelawrenceAbstract:Bone fractures are one of the most common injuries in the USA. Fiberglass tape is a commonly used Casting Material, and many medical professionals apply adjuvants including liquid hand soap, foam sanitizers, and ultrasound gel in the hopes of improving outcomes relating to ease of molding and eventual strength, lamination, and smoothness of cast Material. However, the efficacy of these agents to improve fiberglass cast mechanics has not been scientifically evaluated. The purpose of this study was to assess the mechanical effects of commonly used adjuvants on fiberglass cast Materials. Studies compared regularly shaped samples of water-activated, untreated fiberglass tape (Ossur Techform Premium) to water-activated fiberglass tape treated with one of three commonly used adjuvants (liquid soap, foam hand sanitizer, or ultrasound gel) during lamination. Material stiffness, yield stress, and ultimate load were measured by 3-point bending. These studies demonstrated that that liquid soap and ultrasound gel did not affect fiberglass tape mechanical properties, but alcohol-based foam sanitizer significantly reduced stiffness (− 32.8%), yield stress (− 33.6%), and ultimate load (− 31.0%) of the cast Material as compared to the control group. Regression slopes were not significantly different between groups, suggesting that no adjuvants improved Material curing time. These data suggest that the application of adjuvants is not beneficial and potentially harmful to fiberglass cast behavior. Despite the widespread practice of adjuvant application by medical professionals during Casting, results from the current study suggest that use of these agents for structural enhancement of fiberglass casts is not beneficial and should largely be discouraged.
J. Sato - One of the best experts on this subject based on the ideXlab platform.
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Investigation of long-term reliability for solid insulated switchgear
PES T&D 2012, 2012Co-Authors: J. Sato, T. Shioiri, T. Imai, O. Tagaya, Y. Takei, T. Kuriyama, M. HommaAbstract:SF6 gas is applied widely to medium voltage switchgear because of its high insulation reliability and down-sizing ability. However, SF6 gas was placed on the list of greenhouse gases under the Kyoto Protocol in 1997. Since then, the investigation and development concerning SF6 free or less has carried out activity. Therefore, we focused on solid Materials with higher dielectric strength than SF6, and we have developed solid insulated switchgear (SIS) achieved by molding all main circuit. A new epoxy Casting Material is applied, which contains a great deal of spherical silica and a small amount of rubber particles. This new Material has the high mechanical strength, high thermal resistance, high toughness, and also high dielectric strength because of directly molding the vacuum bottle, as well as reduced size and high reliability. This paper describes about the long-term reliability of SIS using a new epoxy Casting Material. We carried out seismic tests, heat cycle tests, heat shock tests and long-term withstand voltage tests for about 5 years. As a result, it was confirmed that SIS had an excellent characteristics in all tests. The effectiveness of the development Material and the reliability of SIS were verified.
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Material and simulation technology for solid insulated switchgear
Proceedings of the 7th International Conference on Properties and Applications of Dielectric Materials (Cat. No.03CH37417), 2003Co-Authors: T. Shimizu, Shingo Makishima, J. Sato, S Kinoshita, Osamu SakaguchiAbstract:We have developed solid insulated switchgear(SIS), which is designed for SF6-free innovative medium voltage applications. A new epoxy Casting Material is applied, which contains a great deal of spherical silica to reduce viscosity and increase mechanical strength. This Material has the high glass transition temperature, which provides high thermal resistance and also high toughness for directly molding the vacuum interrupter. The switchgear consists of some complicated Casting insulators such as bushings and cable heads. These insulators are manufactured by the high-cycle automatic pressure gelation method. The flow and cure analysis of the Casting Material visualizes the curing process inside the molds and suggests the best manufacturing conditions such as temperature, speed and time.