The Experts below are selected from a list of 1929 Experts worldwide ranked by ideXlab platform
Kazuhiro Nakata - One of the best experts on this subject based on the ideXlab platform.
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effect of welding parameters on microstructure in the stir zone of fsw joints of Aluminum Die Casting alloy
Materials Letters, 2006Co-Authors: Hidetoshi Fujii, Takuya Tsumura, Tamu Komazaki, Kazuhiro NakataAbstract:The effect of the welding speed and the rotation speed on the microstructure in the stir zone has been investigated by measuring the Si particle distribution in the ADC12 alloy. The stir zone has fine recrystallized grains without dendritic structures, and the eutectic Si was uniformly dispersed in the stir zone. The size of the Si particles was statistically determined in the stir zone using image processing. The number of finer Si particles, which is formed by stirring of the tool probe, increases during the FSW. Finer Si particles are distributed more in the bottom than in the other regions, though the size of the Si particles in the base metal is the same in all the regions. The size of the Si particles decreases with increasing welding speed. However, it is not significantly affected by the rotation speed.
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improvement of mechanical properties of Aluminum Die Casting alloy by multi pass friction stir processing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Kazuhiro Nakata, Hidetoshi Fujii, Takuya Tsumura, Tamu KomazakiAbstract:Abstract An improvement in the mechanical properties was accomplished due to the microstructural modification of an Aluminum Die Casting alloy by multi-pass friction stir processing (MP-FSP), which is a solid-state microstructural modification technique using a frictional heat and stirring action. The hardness of the MP-FSP sample is about 20 Hv higher than that of the base metal. The tensile strengths of the MP-FSPed specimens were significantly increased to about 1.7 times versus that of the base metal. This is due not only to the disappearance of the cold flake in the base metal, but also to a structural refinement, such as uniform distribution of Si particles. Thus, the application of the MP-FSP is a very effective method for the mechanical improvement of Aluminum Die Casting alloys.
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three defect types in friction stir welding of Aluminum Die Casting alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Young Gon Kim, Hidetoshi Fujii, Takuya Tsumura, Tamu Komazaki, Kazuhiro NakataAbstract:For different tool plunge downforces, the optimum FSW conditions of Aluminum Die Casting alloy were examined. The higher the tool plunge downforce is, the wider the range of the optimum FSW conditions is. The following three different types of defects are formed, depending on the FSW conditions. (1) A large mass of flash due to the excess heat input; (2) cavity or groove-like defects caused by insufficient heat input; and (3) cavity caused by the abnormal stirring. As for the abnormal stirring, it is clearly seen that the shape of the top part on the advancing side in the stir zone is completely different. For this type of defect, the effect of the tool plunge downforce is small, though the size of the defect due to insufficient heat input significantly decreases with the increasing downforce.
Jessada Wannasin - One of the best experts on this subject based on the ideXlab platform.
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feasibility of semi solid Die Casting of adc12 Aluminum alloy
Transactions of Nonferrous Metals Society of China, 2010Co-Authors: Somjai Janudom, T. Rattanochaikul, R Burapa, Sirikul Wisutmethangoon, Jessada WannasinAbstract:The feasibility of semi-solid Die Casting of ADC12 Aluminum alloy was stuDied. The effects of plunger speed, gate thickness, and solid fraction of the slurry on the defects were determined. The defects investigated are gas and shrinkage porosity. In the experiments, semi-solid slurry was prepared by the gas-induced semi-solid (GISS) technique. Then, the slurry was transferred to the shot sleeve and injected into the Die. The Die and shot sleeve temperatures were kept at 180 °C and 250 °C, respectively. The results show that the samples produced by the GISS Die Casting give little porosity, no blister and uniform microstructure. From all the results, it can be concluded that the GISS process is feasible to apply in the ADC12 Aluminum Die Casting process. In addition, the GISS process can give improved properties such as decreased porosity and increased microstructure uniformity.
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evaluation of solid fraction in a rheocast Aluminum Die Casting alloy by a rapid quenching method
Scripta Materialia, 2008Co-Authors: Jessada Wannasin, R Canyook, R Burapa, L Sikong, Merton C FlemingsAbstract:A new approach to evaluate the solid fraction of semi-solid slurries is reported. The approach applies a thin-channel vacuum mold to rapidly quench semi-solid slurries at different rheoCasting times. The slurry temperatures are analyzed from the cooling curves. The corresponding solid fraction data are obtained from standard quantitative metallography. A correction of the data is then conducted using the average growth layer of the solid particles. The analyzed solid fraction agrees well with the data from the Scheil model.
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Development of the Gas Induced Semi-Solid Metal Process for Aluminum Die Casting Applications
Solid State Phenomena, 2008Co-Authors: Jessada Wannasin, S. Junudom, T. Rattanochaikul, Merton C FlemingsAbstract:A simple and efficient rheoCasting process that has recently been invented is being developed for Aluminum Die Casting applications. The process called Gas Induced Semi-Solid (GISS) utilizes the combination of local rapid heat extraction and agitation achieved by the injection of fine gas bubbles through a graphite diffuser to create semi-solid slurry. In the GISS process, the Die Casting machine and the process cycle remain little changed from those of conventional Die Casting. The GISS unit creates a low solid fraction of semi-solid slurry in the ladle during the ladle transfer to the shot sleeve. The semi-solid slurry is then poured directly into the shot sleeve. This paper presents the detailed description of the process. The results of the semi-solid Die Casting experiments with ADC10 alloy using the GISS process are also reported and discussed.
Hidetoshi Fujii - One of the best experts on this subject based on the ideXlab platform.
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effect of welding parameters on microstructure in the stir zone of fsw joints of Aluminum Die Casting alloy
Materials Letters, 2006Co-Authors: Hidetoshi Fujii, Takuya Tsumura, Tamu Komazaki, Kazuhiro NakataAbstract:The effect of the welding speed and the rotation speed on the microstructure in the stir zone has been investigated by measuring the Si particle distribution in the ADC12 alloy. The stir zone has fine recrystallized grains without dendritic structures, and the eutectic Si was uniformly dispersed in the stir zone. The size of the Si particles was statistically determined in the stir zone using image processing. The number of finer Si particles, which is formed by stirring of the tool probe, increases during the FSW. Finer Si particles are distributed more in the bottom than in the other regions, though the size of the Si particles in the base metal is the same in all the regions. The size of the Si particles decreases with increasing welding speed. However, it is not significantly affected by the rotation speed.
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improvement of mechanical properties of Aluminum Die Casting alloy by multi pass friction stir processing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Kazuhiro Nakata, Hidetoshi Fujii, Takuya Tsumura, Tamu KomazakiAbstract:Abstract An improvement in the mechanical properties was accomplished due to the microstructural modification of an Aluminum Die Casting alloy by multi-pass friction stir processing (MP-FSP), which is a solid-state microstructural modification technique using a frictional heat and stirring action. The hardness of the MP-FSP sample is about 20 Hv higher than that of the base metal. The tensile strengths of the MP-FSPed specimens were significantly increased to about 1.7 times versus that of the base metal. This is due not only to the disappearance of the cold flake in the base metal, but also to a structural refinement, such as uniform distribution of Si particles. Thus, the application of the MP-FSP is a very effective method for the mechanical improvement of Aluminum Die Casting alloys.
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three defect types in friction stir welding of Aluminum Die Casting alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Young Gon Kim, Hidetoshi Fujii, Takuya Tsumura, Tamu Komazaki, Kazuhiro NakataAbstract:For different tool plunge downforces, the optimum FSW conditions of Aluminum Die Casting alloy were examined. The higher the tool plunge downforce is, the wider the range of the optimum FSW conditions is. The following three different types of defects are formed, depending on the FSW conditions. (1) A large mass of flash due to the excess heat input; (2) cavity or groove-like defects caused by insufficient heat input; and (3) cavity caused by the abnormal stirring. As for the abnormal stirring, it is clearly seen that the shape of the top part on the advancing side in the stir zone is completely different. For this type of defect, the effect of the tool plunge downforce is small, though the size of the defect due to insufficient heat input significantly decreases with the increasing downforce.
Tamu Komazaki - One of the best experts on this subject based on the ideXlab platform.
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effect of welding parameters on microstructure in the stir zone of fsw joints of Aluminum Die Casting alloy
Materials Letters, 2006Co-Authors: Hidetoshi Fujii, Takuya Tsumura, Tamu Komazaki, Kazuhiro NakataAbstract:The effect of the welding speed and the rotation speed on the microstructure in the stir zone has been investigated by measuring the Si particle distribution in the ADC12 alloy. The stir zone has fine recrystallized grains without dendritic structures, and the eutectic Si was uniformly dispersed in the stir zone. The size of the Si particles was statistically determined in the stir zone using image processing. The number of finer Si particles, which is formed by stirring of the tool probe, increases during the FSW. Finer Si particles are distributed more in the bottom than in the other regions, though the size of the Si particles in the base metal is the same in all the regions. The size of the Si particles decreases with increasing welding speed. However, it is not significantly affected by the rotation speed.
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improvement of mechanical properties of Aluminum Die Casting alloy by multi pass friction stir processing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Kazuhiro Nakata, Hidetoshi Fujii, Takuya Tsumura, Tamu KomazakiAbstract:Abstract An improvement in the mechanical properties was accomplished due to the microstructural modification of an Aluminum Die Casting alloy by multi-pass friction stir processing (MP-FSP), which is a solid-state microstructural modification technique using a frictional heat and stirring action. The hardness of the MP-FSP sample is about 20 Hv higher than that of the base metal. The tensile strengths of the MP-FSPed specimens were significantly increased to about 1.7 times versus that of the base metal. This is due not only to the disappearance of the cold flake in the base metal, but also to a structural refinement, such as uniform distribution of Si particles. Thus, the application of the MP-FSP is a very effective method for the mechanical improvement of Aluminum Die Casting alloys.
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three defect types in friction stir welding of Aluminum Die Casting alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Young Gon Kim, Hidetoshi Fujii, Takuya Tsumura, Tamu Komazaki, Kazuhiro NakataAbstract:For different tool plunge downforces, the optimum FSW conditions of Aluminum Die Casting alloy were examined. The higher the tool plunge downforce is, the wider the range of the optimum FSW conditions is. The following three different types of defects are formed, depending on the FSW conditions. (1) A large mass of flash due to the excess heat input; (2) cavity or groove-like defects caused by insufficient heat input; and (3) cavity caused by the abnormal stirring. As for the abnormal stirring, it is clearly seen that the shape of the top part on the advancing side in the stir zone is completely different. For this type of defect, the effect of the tool plunge downforce is small, though the size of the defect due to insufficient heat input significantly decreases with the increasing downforce.
Takuya Tsumura - One of the best experts on this subject based on the ideXlab platform.
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effect of welding parameters on microstructure in the stir zone of fsw joints of Aluminum Die Casting alloy
Materials Letters, 2006Co-Authors: Hidetoshi Fujii, Takuya Tsumura, Tamu Komazaki, Kazuhiro NakataAbstract:The effect of the welding speed and the rotation speed on the microstructure in the stir zone has been investigated by measuring the Si particle distribution in the ADC12 alloy. The stir zone has fine recrystallized grains without dendritic structures, and the eutectic Si was uniformly dispersed in the stir zone. The size of the Si particles was statistically determined in the stir zone using image processing. The number of finer Si particles, which is formed by stirring of the tool probe, increases during the FSW. Finer Si particles are distributed more in the bottom than in the other regions, though the size of the Si particles in the base metal is the same in all the regions. The size of the Si particles decreases with increasing welding speed. However, it is not significantly affected by the rotation speed.
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improvement of mechanical properties of Aluminum Die Casting alloy by multi pass friction stir processing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Kazuhiro Nakata, Hidetoshi Fujii, Takuya Tsumura, Tamu KomazakiAbstract:Abstract An improvement in the mechanical properties was accomplished due to the microstructural modification of an Aluminum Die Casting alloy by multi-pass friction stir processing (MP-FSP), which is a solid-state microstructural modification technique using a frictional heat and stirring action. The hardness of the MP-FSP sample is about 20 Hv higher than that of the base metal. The tensile strengths of the MP-FSPed specimens were significantly increased to about 1.7 times versus that of the base metal. This is due not only to the disappearance of the cold flake in the base metal, but also to a structural refinement, such as uniform distribution of Si particles. Thus, the application of the MP-FSP is a very effective method for the mechanical improvement of Aluminum Die Casting alloys.
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three defect types in friction stir welding of Aluminum Die Casting alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: Young Gon Kim, Hidetoshi Fujii, Takuya Tsumura, Tamu Komazaki, Kazuhiro NakataAbstract:For different tool plunge downforces, the optimum FSW conditions of Aluminum Die Casting alloy were examined. The higher the tool plunge downforce is, the wider the range of the optimum FSW conditions is. The following three different types of defects are formed, depending on the FSW conditions. (1) A large mass of flash due to the excess heat input; (2) cavity or groove-like defects caused by insufficient heat input; and (3) cavity caused by the abnormal stirring. As for the abnormal stirring, it is clearly seen that the shape of the top part on the advancing side in the stir zone is completely different. For this type of defect, the effect of the tool plunge downforce is small, though the size of the defect due to insufficient heat input significantly decreases with the increasing downforce.
