The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
K.h. Chai - One of the best experts on this subject based on the ideXlab platform.
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Interfacial segregation, nucleation and texture development in 3% silicon steel
Acta Materialia, 2003Co-Authors: Y.s. Choi, K.h. ChaiAbstract:Abstract In inhibitor-free 3% Si–Fe alloys containing sulfur, the matter which the Final main texture after annealing becomes among the {1 0 0}〈u v w〉, {1 1 0}〈0 0 1〉 and {1 1 0}〈u v w〉 components depends on the combination of various factors: Final Reduction, heating rate, flow rate of hydrogen and bulk content of sulfur. With increasing Final Reduction and heating rate, the Final main texture after annealing tends to be transited from the {1 1 0}〈u v w〉 to the {1 1 0}〈0 0 1〉 and then followed by the {1 0 0}〈u v w〉 component. This is due to the active surface-energy-induced selective growth of the {1 0 0}〈u v w〉 grains that makes the survival and selective growth of the {1 1 0} grains difficult. On the viewpoints of the nucleation and the selective growth, a higher flow rate of hydrogen and a lower bulk content of sulfur may result in the transition in Final main texture of the {1 0 0}〈u v w〉 to the {1 1 0}〈0 0 1〉 and subsequently to the {1 1 0}〈u v w〉 component after annealing.
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Interfacial segregation kinetics of sulfur and magnetic induction influenced by hydrogen flow rate in thin-gauged 3% Si-Fe strip
IEEE Transactions on Magnetics, 2002Co-Authors: Y.s. Choi, K.h. ChaiAbstract:Effects of flow rate of hydrogen and Final Reduction on Final texture and magnetic induction have been investigated in 3% Si-Fe alloy strips containing 90-ppm sulfur. After Final annealing under a flowing hydrogen atmosphere of 10 l/min, the strip showed a magnetic induction value (B/sub 10/) higher than 1.9 T, whereas only about 1.6 T was obtained at a flow rate of 3 l/min. Within the range of Final Reduction in thickness of 30%-60%, the Final texture and the magnetic induction revealed little dependence on Final Reduction. Auger electron spectroscopy indicated that the strong dependence of magnetic induction on the flow rate of hydrogen was due to the difference in segregation kinetics of sulfur at the strip surface. The selective growth kinetics also supported a correlation between segregation kinetics of sulfur, texture development, and magnetic induction.
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Selective nucleation and growth in 3% silicon steel
IEEE Transactions on Magnetics, 2002Co-Authors: Y.s. Choi, K.h. ChaiAbstract:Due to the stronger bond strength of the Fe-S molecule than that of the Fe-Fe molecule, at the stage of nucleation the surface-segregated sulfur hinders the systematical movement of matrix atoms into the exact positions at the surface for the formation of the [110][001]. When the [110] grains form selectively at the strip surface, even a subdivision of a low concentration of surface-segregated sulfur determines, therefore, the degree of disturbance against movement of matrix atoms and, thus, the direction of the [110]: the [110][001] at a much lower concentration of surface-segregated sulfur and the [110][uvw]/sub /spl ne/[001]/ under a lower condition of segregated sulfur. Due to the relatively higher mobility of matrix atoms, the probability that, at a fixed Final Reduction, the [110] grains survive through the selective growth of [100] grains and have Finally a chance for selective growth decreases with increasing heating rate.
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Initial recrystallization texture and magnetic induction in single-oriented electrical steel
IEEE Transactions on Magnetics, 2001Co-Authors: K.h. Chai, J.g. Na, I.k. SongAbstract:Initial recrystallization texture is influenced by the bulk content of sulfur and by the Final Reduction. At a given bulk content of sulfur, a lower Final Reduction is favorable for obtaining the initial {011} Goss texture. Under a fixed Final Reduction, a lower bulk content of sulfur is good for this purpose. As the intensity of initial Goss texture increases, it is easier to obtain magnetic induction (B/sub 10/). This is because the probability, that the initial Goss grains survive within the time range of highly segregated sulfur and have a chance for surface-energy-induced selective growth, becomes higher under the later segregated-sulfur-free condition.
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Correlation between interfacial segregation and surface-energy-induced selective grain growth in 3% silicon–iron alloy
Acta Materialia, 2000Co-Authors: K.h. Chai, J.g. NaAbstract:Abstract Effects of Final Reduction and interfacial segregation of sulfur on surface-energy-induced selective grain growth have been investigated in 3% silicon–iron alloy strips with various bulk content of sulfur. Interfacial segregation kinetics of sulfur varies with annealing atmosphere: a convex profile under vacuum or hydrogen and a gradual increase under argon. This is because the segregated sulfur evaporates or gasifies to hydrogen sulfide during Final vacuum or hydrogen annealing, resulting in a sulfur-depleted zone just below the strip surface. The surface-energy-induced selective growth of a grain at time t is determined by the concentration of segregated sulfur. The selective growth rate depends on the combined effect of the segregated sulfur and the Final Reduction that determines the average grain size. For obtaining (110)[001] Goss texture, the Final Reduction should, therefore, be controlled, depending on the bulk content of sulfur which influences directly the segregation kinetics of sulfur and thus the texture development.
Desimir Markovic - One of the best experts on this subject based on the ideXlab platform.
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influence of thermomechanical treatment on the hardening mechanisms and structural changes of a cast cu 6 6 wt ag alloy
Materials & Design, 2010Co-Authors: Svetlana Nestorovic, Ivana Markovic, Desimir MarkovicAbstract:Abstract Investigations were carried out on the cast samples of Cu–6.6 wt.%Ag alloy, as well as pure copper samples, for the sake of comparison. Cast samples of copper and alloy were subjected to the same thermomechanical treatment. The thermomechanical treatment included the homogenized annealing, preFinal cold rolling, solution annealing, Final cold rolling with a Final Reduction of 20%, 40% and 60% as well as the isochronal and isothermal annealing up to the recrystallization temperature. Influence of thermomechanical treatment on the hardening mechanisms and structural changes of cast Cu–6.6 wt.%Ag alloy has been investigated for the hardness and electrical conductivity measurements as well as optical microscopy. The study has shown that the anneal hardening effect appeared on the cast Cu–6.6 wt.%Ag alloy in the temperature range of 160–400 °C and was followed by an increase in the hardness and electrical conductivity.
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Influence of degree of deformation in rolling on anneal hardening effect of a cast copper alloy
Bulletin of Materials Science, 2003Co-Authors: Svetlana Nestorovic, Desimir Markovic, Ljubica S. IvanićAbstract:This paper reports results of investigations carried out on a cast copper alloy containing 8 at.% Al. The alloy, and pure copper for the sake of comparison, were subjected to cold rolling with a Final Reduction of 30, 50 or 70%.
Svetlana Nestorovic - One of the best experts on this subject based on the ideXlab platform.
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INFLUENCE OF THERMOMECHANICAL TREATMENT ON THE ANNEAL HARDENING MECHANISM OF A CAST COPPER-SILVER ALLOY
2020Co-Authors: Svetlana Nestorovic, Ivana Rangelov, Ljubica S. IvanićAbstract:This paper reports results of investigation carried out on a cast copper-silver alloy containing 4at%Ag. The alloy and pure copper for the sake of comparison, were subjected to cold rolling with a Final Reduction of 20, 40 or 60%. The cold rolled copper and copper-silver alloy samples were isochronally and isothermally annealed up to the recrystallization temperature. The hardness, strength and electrical conductivity were measured and DTA analyses performed. Anneal hardening effect was observed in the alloy in the temperature range 160-300 0 C, followed by an increase in the hardness and electrical conductivity. The amount of strengthening increases with increasing degree of prior cold work. The DTA analysis shows the exothermic character of this effect.
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influence of thermomechanical treatment on the hardening mechanisms and structural changes of a cast cu 6 6 wt ag alloy
Materials & Design, 2010Co-Authors: Svetlana Nestorovic, Ivana Markovic, Desimir MarkovicAbstract:Abstract Investigations were carried out on the cast samples of Cu–6.6 wt.%Ag alloy, as well as pure copper samples, for the sake of comparison. Cast samples of copper and alloy were subjected to the same thermomechanical treatment. The thermomechanical treatment included the homogenized annealing, preFinal cold rolling, solution annealing, Final cold rolling with a Final Reduction of 20%, 40% and 60% as well as the isochronal and isothermal annealing up to the recrystallization temperature. Influence of thermomechanical treatment on the hardening mechanisms and structural changes of cast Cu–6.6 wt.%Ag alloy has been investigated for the hardness and electrical conductivity measurements as well as optical microscopy. The study has shown that the anneal hardening effect appeared on the cast Cu–6.6 wt.%Ag alloy in the temperature range of 160–400 °C and was followed by an increase in the hardness and electrical conductivity.
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Influence of degree of deformation in rolling on anneal hardening effect of a cast copper alloy
Bulletin of Materials Science, 2003Co-Authors: Svetlana Nestorovic, Desimir Markovic, Ljubica S. IvanićAbstract:This paper reports results of investigations carried out on a cast copper alloy containing 8 at.% Al. The alloy, and pure copper for the sake of comparison, were subjected to cold rolling with a Final Reduction of 30, 50 or 70%.
Y.s. Choi - One of the best experts on this subject based on the ideXlab platform.
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Interfacial segregation, nucleation and texture development in 3% silicon steel
Acta Materialia, 2003Co-Authors: Y.s. Choi, K.h. ChaiAbstract:Abstract In inhibitor-free 3% Si–Fe alloys containing sulfur, the matter which the Final main texture after annealing becomes among the {1 0 0}〈u v w〉, {1 1 0}〈0 0 1〉 and {1 1 0}〈u v w〉 components depends on the combination of various factors: Final Reduction, heating rate, flow rate of hydrogen and bulk content of sulfur. With increasing Final Reduction and heating rate, the Final main texture after annealing tends to be transited from the {1 1 0}〈u v w〉 to the {1 1 0}〈0 0 1〉 and then followed by the {1 0 0}〈u v w〉 component. This is due to the active surface-energy-induced selective growth of the {1 0 0}〈u v w〉 grains that makes the survival and selective growth of the {1 1 0} grains difficult. On the viewpoints of the nucleation and the selective growth, a higher flow rate of hydrogen and a lower bulk content of sulfur may result in the transition in Final main texture of the {1 0 0}〈u v w〉 to the {1 1 0}〈0 0 1〉 and subsequently to the {1 1 0}〈u v w〉 component after annealing.
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Interfacial segregation kinetics of sulfur and magnetic induction influenced by hydrogen flow rate in thin-gauged 3% Si-Fe strip
IEEE Transactions on Magnetics, 2002Co-Authors: Y.s. Choi, K.h. ChaiAbstract:Effects of flow rate of hydrogen and Final Reduction on Final texture and magnetic induction have been investigated in 3% Si-Fe alloy strips containing 90-ppm sulfur. After Final annealing under a flowing hydrogen atmosphere of 10 l/min, the strip showed a magnetic induction value (B/sub 10/) higher than 1.9 T, whereas only about 1.6 T was obtained at a flow rate of 3 l/min. Within the range of Final Reduction in thickness of 30%-60%, the Final texture and the magnetic induction revealed little dependence on Final Reduction. Auger electron spectroscopy indicated that the strong dependence of magnetic induction on the flow rate of hydrogen was due to the difference in segregation kinetics of sulfur at the strip surface. The selective growth kinetics also supported a correlation between segregation kinetics of sulfur, texture development, and magnetic induction.
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Selective nucleation and growth in 3% silicon steel
IEEE Transactions on Magnetics, 2002Co-Authors: Y.s. Choi, K.h. ChaiAbstract:Due to the stronger bond strength of the Fe-S molecule than that of the Fe-Fe molecule, at the stage of nucleation the surface-segregated sulfur hinders the systematical movement of matrix atoms into the exact positions at the surface for the formation of the [110][001]. When the [110] grains form selectively at the strip surface, even a subdivision of a low concentration of surface-segregated sulfur determines, therefore, the degree of disturbance against movement of matrix atoms and, thus, the direction of the [110]: the [110][001] at a much lower concentration of surface-segregated sulfur and the [110][uvw]/sub /spl ne/[001]/ under a lower condition of segregated sulfur. Due to the relatively higher mobility of matrix atoms, the probability that, at a fixed Final Reduction, the [110] grains survive through the selective growth of [100] grains and have Finally a chance for selective growth decreases with increasing heating rate.
J. M. Oh - One of the best experts on this subject based on the ideXlab platform.
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Effect of preannealing on Final texture and magnetic induction in thin-gauged 3% Si–Fe strips containing 0.1% Mn and 0.011% S
Journal of Applied Physics, 2007Co-Authors: J. M. OhAbstract:In 0.1mm thick 3% Si–Fe strips containing 0.1% manganese and 0.011% sulfur, the preannealed strips were composed of {110} grains after Final annealing at 1200°C, while the other strips without preannealing consisted of {100} or {111} grains. This is due to the difference in surface-energy-induced selective growth kinetics in which the main governing factor is probably by the primary grain size. In the preannealed strip with a higher Final Reduction, the relatively smaller grain size effect produced the decrease in total number of the {110} grains and thus the sharper {110}⟨001⟩ Final texture favorable for the higher magnetic induction.