The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Sung S Park - One of the best experts on this subject based on the ideXlab platform.
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development of creep resistant die cast mg sn al si alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Dae H Kang, Sung S ParkAbstract:Abstract A study has been made on the tensile properties and high temperature properties of die cast Mg–Sn–Al–Si (TAS831) alloy. The microstructure of TAS831 alloy is characterized by the presence of thermally stable Mg 2 Sn particles within matrix and along grain boundaries. It also contains a small volume fraction of thermally stable Mg 2 Si particles. It has been shown that TAS831 alloy has better combinations of tensile properties at room and elevated temperatures than die cast AZ91 alloy. Creep properties of TAS831 alloy are also superior to those of AZ91 alloy. Analyses of creep behavior and load-relaxation behavior at elevated temperatures in the context of internal variable theory indicate that the presence of thermally stable dispersoids in TAS831 alloy increases the resistance to Dislocation Movement, thereby improving creep properties over those of AZ91 alloy.
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development of creep resistant die cast mg sn al si alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Dae H Kang, Sung S Park, Nack J KimAbstract:A study has been made on the tensile properties and high temperature properties of die cast Mg–Sn–Al–Si (TAS831) alloy. The microstructure of TAS831 alloy is characterized by the presence of thermally stable Mg2Sn particles within matrix and along grain boundaries. It also contains a small volume fraction of thermally stable Mg2Si particles. It has been shown that TAS831 alloy has better combinations of tensile properties at room and elevated temperatures than die cast AZ91 alloy. Creep properties of TAS831 alloy are also superior to those of AZ91 alloy. Analyses of creep behavior and load-relaxation behavior at elevated temperatures in the context of internal variable theory indicate that the presence of thermally stable dispersoids in TAS831 alloy increases the resistance to Dislocation Movement, thereby improving creep properties over those of AZ91 alloy. © 2005 Elsevier B.V. All rights reserved.
Dae H Kang - One of the best experts on this subject based on the ideXlab platform.
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development of creep resistant die cast mg sn al si alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Dae H Kang, Sung S ParkAbstract:Abstract A study has been made on the tensile properties and high temperature properties of die cast Mg–Sn–Al–Si (TAS831) alloy. The microstructure of TAS831 alloy is characterized by the presence of thermally stable Mg 2 Sn particles within matrix and along grain boundaries. It also contains a small volume fraction of thermally stable Mg 2 Si particles. It has been shown that TAS831 alloy has better combinations of tensile properties at room and elevated temperatures than die cast AZ91 alloy. Creep properties of TAS831 alloy are also superior to those of AZ91 alloy. Analyses of creep behavior and load-relaxation behavior at elevated temperatures in the context of internal variable theory indicate that the presence of thermally stable dispersoids in TAS831 alloy increases the resistance to Dislocation Movement, thereby improving creep properties over those of AZ91 alloy.
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development of creep resistant die cast mg sn al si alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Dae H Kang, Sung S Park, Nack J KimAbstract:A study has been made on the tensile properties and high temperature properties of die cast Mg–Sn–Al–Si (TAS831) alloy. The microstructure of TAS831 alloy is characterized by the presence of thermally stable Mg2Sn particles within matrix and along grain boundaries. It also contains a small volume fraction of thermally stable Mg2Si particles. It has been shown that TAS831 alloy has better combinations of tensile properties at room and elevated temperatures than die cast AZ91 alloy. Creep properties of TAS831 alloy are also superior to those of AZ91 alloy. Analyses of creep behavior and load-relaxation behavior at elevated temperatures in the context of internal variable theory indicate that the presence of thermally stable dispersoids in TAS831 alloy increases the resistance to Dislocation Movement, thereby improving creep properties over those of AZ91 alloy. © 2005 Elsevier B.V. All rights reserved.
Nack J Kim - One of the best experts on this subject based on the ideXlab platform.
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development of creep resistant die cast mg sn al si alloy
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005Co-Authors: Dae H Kang, Sung S Park, Nack J KimAbstract:A study has been made on the tensile properties and high temperature properties of die cast Mg–Sn–Al–Si (TAS831) alloy. The microstructure of TAS831 alloy is characterized by the presence of thermally stable Mg2Sn particles within matrix and along grain boundaries. It also contains a small volume fraction of thermally stable Mg2Si particles. It has been shown that TAS831 alloy has better combinations of tensile properties at room and elevated temperatures than die cast AZ91 alloy. Creep properties of TAS831 alloy are also superior to those of AZ91 alloy. Analyses of creep behavior and load-relaxation behavior at elevated temperatures in the context of internal variable theory indicate that the presence of thermally stable dispersoids in TAS831 alloy increases the resistance to Dislocation Movement, thereby improving creep properties over those of AZ91 alloy. © 2005 Elsevier B.V. All rights reserved.
Colin J. Humphreys - One of the best experts on this subject based on the ideXlab platform.
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Dislocation climb in c plane aln films
Applied Physics Express, 2011Co-Authors: Menno J. Kappers, Colin J. Humphreys, Y Zhang, M A MoramAbstract:A series of AlN films of increasing thickness (up to 4 µm) were grown on c-plane sapphire by metalorganic vapour phase epitaxy. Plan-view transmission electron microscopy (TEM) images reveal that the Dislocation density at the film surface reduces with increasing film thickness, whereas cross-sectional TEM data reveal that Dislocation reduction continues to occur beneath the film surface during growth, resulting in the preferential annihilation of c-type and/or (a+c)-type Dislocations. We conclude that Dislocation Movement occurs by climb during AlN growth.
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The effects of Si doping on Dislocation Movement and tensile stress in GaN films
Journal of Applied Physics, 2011Co-Authors: M A Moram, Menno J. Kappers, Fabien Massabuau, Rachel A. Oliver, Colin J. HumphreysAbstract:Dislocations in undoped GaN move in response to the in-plane tensile stress present during film growth. Dislocation Movement during growth relieves tensile stress, produces arrays of a-type Dislocations and reduces the overall Dislocation density, with preferential reduction of (a+c)-type Dislocations. However, Si-doping limits Dislocation Movement, limiting the relief of the tensile stress that develops during growth and limiting Dislocation reduction, probably due to the formation of Si impurity atmospheres at Dislocations. Consequently, Si-doped films are under relatively greater tensile stress compared to undoped GaN films grown under similar conditions. Alternative dopants could be chosen to reduce tensile stress development, such as Ge.
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Dislocation Movement in GaN films
Applied Physics Letters, 2010Co-Authors: M A Moram, M. Häberlen, Thomas C Sadler, Menno J. Kappers, Colin J. HumphreysAbstract:We demonstrate that significant Dislocation Movement occurs below the surface of heteroepitaxial c-plane {GaN} films during their growth by metalorganic vapor phase epitaxy. Dislocations move primarily by vacancy-assisted climb, which appears to be driven by the high in-plane biaxial stresses present during growth. Annealing low Dislocation density (4.3×108 cm−2) {GaN} films promotes Dislocation climb and thus reduces both Dislocation densities and in-plane stresses (at high temperatures), independent of epilayer growth conditions.
M A Moram - One of the best experts on this subject based on the ideXlab platform.
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Dislocation climb in c plane aln films
Applied Physics Express, 2011Co-Authors: Menno J. Kappers, Colin J. Humphreys, Y Zhang, M A MoramAbstract:A series of AlN films of increasing thickness (up to 4 µm) were grown on c-plane sapphire by metalorganic vapour phase epitaxy. Plan-view transmission electron microscopy (TEM) images reveal that the Dislocation density at the film surface reduces with increasing film thickness, whereas cross-sectional TEM data reveal that Dislocation reduction continues to occur beneath the film surface during growth, resulting in the preferential annihilation of c-type and/or (a+c)-type Dislocations. We conclude that Dislocation Movement occurs by climb during AlN growth.
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The effects of Si doping on Dislocation Movement and tensile stress in GaN films
Journal of Applied Physics, 2011Co-Authors: M A Moram, Menno J. Kappers, Fabien Massabuau, Rachel A. Oliver, Colin J. HumphreysAbstract:Dislocations in undoped GaN move in response to the in-plane tensile stress present during film growth. Dislocation Movement during growth relieves tensile stress, produces arrays of a-type Dislocations and reduces the overall Dislocation density, with preferential reduction of (a+c)-type Dislocations. However, Si-doping limits Dislocation Movement, limiting the relief of the tensile stress that develops during growth and limiting Dislocation reduction, probably due to the formation of Si impurity atmospheres at Dislocations. Consequently, Si-doped films are under relatively greater tensile stress compared to undoped GaN films grown under similar conditions. Alternative dopants could be chosen to reduce tensile stress development, such as Ge.
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Dislocation Movement in GaN films
Applied Physics Letters, 2010Co-Authors: M A Moram, M. Häberlen, Thomas C Sadler, Menno J. Kappers, Colin J. HumphreysAbstract:We demonstrate that significant Dislocation Movement occurs below the surface of heteroepitaxial c-plane {GaN} films during their growth by metalorganic vapor phase epitaxy. Dislocations move primarily by vacancy-assisted climb, which appears to be driven by the high in-plane biaxial stresses present during growth. Annealing low Dislocation density (4.3×108 cm−2) {GaN} films promotes Dislocation climb and thus reduces both Dislocation densities and in-plane stresses (at high temperatures), independent of epilayer growth conditions.