The Experts below are selected from a list of 5295 Experts worldwide ranked by ideXlab platform
S Nemecek - One of the best experts on this subject based on the ideXlab platform.
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effect of Deformation Condition on structure development in nickel base alloy
Journal of Materials Processing Technology, 2007Co-Authors: Panyawat Wangyao, Libor Kraus, Jozef Zrnik, S NemecekAbstract:Abstract This research provides an attempt to achieve uniform grain structure by recrystallization process in NiMoCr alloy after different hot- and cold-working application. The changes in microstructure resulting from thermomechanical processing were investigated by optical microscopy. The results showed that homogeneity of the recrystallized structure is strongly related to the amount of sample reduction imposed during hot working and to the period of annealing time. Furthermore, the results illustrate that the recrystallized structure at the surface was finer, than in the interior of the sample. This is due the specimen surface, which is more strain exposed for applied Deformation and driving force for primary recrystalization in sample surface area is therefore higher than in central part of samples. Then, using conventional two-step hot rolling, the expected uniform recrystallized microstructure could not be obtained across the width of slab. An unfavourable contribution at recrystalization process was observed from initial grain size heterogeneity of as-cast ingot structure. However, after additional introduction of cold rolling, which followed hot working the more uniform recrystallized grain structure was achieved after recrystallization annealing.
Panyawat Wangyao - One of the best experts on this subject based on the ideXlab platform.
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effect of Deformation Condition on structure development in nickel base alloy
Journal of Materials Processing Technology, 2007Co-Authors: Panyawat Wangyao, Libor Kraus, Jozef Zrnik, S NemecekAbstract:Abstract This research provides an attempt to achieve uniform grain structure by recrystallization process in NiMoCr alloy after different hot- and cold-working application. The changes in microstructure resulting from thermomechanical processing were investigated by optical microscopy. The results showed that homogeneity of the recrystallized structure is strongly related to the amount of sample reduction imposed during hot working and to the period of annealing time. Furthermore, the results illustrate that the recrystallized structure at the surface was finer, than in the interior of the sample. This is due the specimen surface, which is more strain exposed for applied Deformation and driving force for primary recrystalization in sample surface area is therefore higher than in central part of samples. Then, using conventional two-step hot rolling, the expected uniform recrystallized microstructure could not be obtained across the width of slab. An unfavourable contribution at recrystalization process was observed from initial grain size heterogeneity of as-cast ingot structure. However, after additional introduction of cold rolling, which followed hot working the more uniform recrystallized grain structure was achieved after recrystallization annealing.
H E Hu - One of the best experts on this subject based on the ideXlab platform.
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comparative study of hot processing maps for 6061 aluminium alloy constructed from power constitutive equation and hyperbolic sine constitutive equation
Materials Science and Technology, 2014Co-Authors: H E Hu, Xinyun Wang, L DengAbstract:Two hot-processing maps were constructed from different constitutive equations using high temperature compression data to optimise hot-processing parameters for 6061 aluminium alloy. The results show that the flow behaviour of the alloy may be represented by a hyperbolic sine-type equation with Deformation activation energy of 343·7 kJ mol−1. Dynamic recovery and dynamic recrystallisation concurrently proceeded during high temperature Deformation of the alloy. The hot-processing map constructed from the hyperbolic sine constitutive equation is more suitable for optimising hot-processing parameters and for controlling the microstructure of the alloy. High Deformation temperature and low strain rate favour the hot workability of the alloy. The optimum Deformation Condition for the alloy is 753 K/0·001 s−1. The instability domain occurs at lower Deformation temperature than 653 K.
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effect of Deformation Condition on plastic anisotropy of as rolled 7050 aluminum alloy plate
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2009Co-Authors: Wang Xinyun, H E Hu, Xia JuchenAbstract:Abstract Plastic anisotropy of the as-rolled 7050 aluminum alloy plate was investigated by tensile tests conducted at different temperatures (340 and 460 °C) and different strain rates of 1.0 × 10 −4 , 1.0 × 10 −2 , 0.1, and 1 s −1 . The results show that the plastic strain ratio of the as-rolled 7050 aluminum alloy plate deformed at 340 °C is not sensitive to strain rate, which increases with increasing strain rate when the alloy was deformed at 460 °C. Alloy elements of the alloy deformed at 460 °C and different strain rates are in solution. The plastic strain ratio of the alloy deformed at 460 °C was affected by texture components, especially the Brass orientation {0 1 1}〈2 1 1〉. Dynamic precipitation appears when the alloy was deformed at 340 °C and different strain rates, and the alloy deformed is in over aged Condition. Microstructure is the main influence of plastic anisotropy of the alloy deformed at 340 °C.
Jozef Zrnik - One of the best experts on this subject based on the ideXlab platform.
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effect of Deformation Condition on structure development in nickel base alloy
Journal of Materials Processing Technology, 2007Co-Authors: Panyawat Wangyao, Libor Kraus, Jozef Zrnik, S NemecekAbstract:Abstract This research provides an attempt to achieve uniform grain structure by recrystallization process in NiMoCr alloy after different hot- and cold-working application. The changes in microstructure resulting from thermomechanical processing were investigated by optical microscopy. The results showed that homogeneity of the recrystallized structure is strongly related to the amount of sample reduction imposed during hot working and to the period of annealing time. Furthermore, the results illustrate that the recrystallized structure at the surface was finer, than in the interior of the sample. This is due the specimen surface, which is more strain exposed for applied Deformation and driving force for primary recrystalization in sample surface area is therefore higher than in central part of samples. Then, using conventional two-step hot rolling, the expected uniform recrystallized microstructure could not be obtained across the width of slab. An unfavourable contribution at recrystalization process was observed from initial grain size heterogeneity of as-cast ingot structure. However, after additional introduction of cold rolling, which followed hot working the more uniform recrystallized grain structure was achieved after recrystallization annealing.
Libor Kraus - One of the best experts on this subject based on the ideXlab platform.
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effect of Deformation Condition on structure development in nickel base alloy
Journal of Materials Processing Technology, 2007Co-Authors: Panyawat Wangyao, Libor Kraus, Jozef Zrnik, S NemecekAbstract:Abstract This research provides an attempt to achieve uniform grain structure by recrystallization process in NiMoCr alloy after different hot- and cold-working application. The changes in microstructure resulting from thermomechanical processing were investigated by optical microscopy. The results showed that homogeneity of the recrystallized structure is strongly related to the amount of sample reduction imposed during hot working and to the period of annealing time. Furthermore, the results illustrate that the recrystallized structure at the surface was finer, than in the interior of the sample. This is due the specimen surface, which is more strain exposed for applied Deformation and driving force for primary recrystalization in sample surface area is therefore higher than in central part of samples. Then, using conventional two-step hot rolling, the expected uniform recrystallized microstructure could not be obtained across the width of slab. An unfavourable contribution at recrystalization process was observed from initial grain size heterogeneity of as-cast ingot structure. However, after additional introduction of cold rolling, which followed hot working the more uniform recrystallized grain structure was achieved after recrystallization annealing.