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Y C Wu - One of the best experts on this subject based on the ideXlab platform.
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the yielding deformation and fracture behavior for the Widmanstatten Structure of ti 8al 1mo 1v alloy upon high speed impact
Journal of Alloys and Compounds, 2019Co-Authors: C Zhao, Z H Wang, J W Qiao, Y C WuAbstract:Abstract The yielding, deformation and fracture behavior for the Widmanstatten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact were studied through characterization and discussion. Seven strain rates ranging from 870 s−1 to 3300 s−1 were applied. The results show that: The yield strength of Widmanstatten Structure shows two distinct changing stages among the whole range of strain rates. Under the strain rates below 2250 s−1, Widmanstatten Structure exhibits positive strain rate sensitivity. Surprisingly, under the strain rates from 2250 s−1 to 3300 s−1, it shows negative strain rate sensitivity. The increasing importance of twinning in the initiation of plastic deformation with higher strain rate is deemed as the reason causing this phenomenon. The dynamic compression behavior of Widmanstatten Structure is described by J-C model, which shows unstable prediction performance. Adiabatic shearing band starts forming under the strain rates above 1950 s−1, from which the fracture behavior of Widmanstatten Structure is analyzed. An interesting phenomenon is that the adiabatic shearing band thicknesses at different locations of specimen can be obviously different. This is attributed to the relative orientation of α lamellae to the biggest shear stress plane. Saw-tooth chips start forming at the two end faces of specimen under the strain rates above 2500 s−1, and its formation mechanism is thoroughly discussed. Adiabatic shearing band after post annealing was characterized by EBSD, which shows recrystallized grains with gradient diameters. In addition, it is found that the Burgers orientation relationship of the microStructure outside adiabatic shearing band was generally retained during the dynamic loading and post-annealing process.
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The yielding, deformation and fracture behavior for the Widmanstätten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact
Journal of Alloys and Compounds, 2019Co-Authors: C Zhao, Z H Wang, Junwei Qiao, Y C WuAbstract:Abstract The yielding, deformation and fracture behavior for the Widmanstatten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact were studied through characterization and discussion. Seven strain rates ranging from 870 s−1 to 3300 s−1 were applied. The results show that: The yield strength of Widmanstatten Structure shows two distinct changing stages among the whole range of strain rates. Under the strain rates below 2250 s−1, Widmanstatten Structure exhibits positive strain rate sensitivity. Surprisingly, under the strain rates from 2250 s−1 to 3300 s−1, it shows negative strain rate sensitivity. The increasing importance of twinning in the initiation of plastic deformation with higher strain rate is deemed as the reason causing this phenomenon. The dynamic compression behavior of Widmanstatten Structure is described by J-C model, which shows unstable prediction performance. Adiabatic shearing band starts forming under the strain rates above 1950 s−1, from which the fracture behavior of Widmanstatten Structure is analyzed. An interesting phenomenon is that the adiabatic shearing band thicknesses at different locations of specimen can be obviously different. This is attributed to the relative orientation of α lamellae to the biggest shear stress plane. Saw-tooth chips start forming at the two end faces of specimen under the strain rates above 2500 s−1, and its formation mechanism is thoroughly discussed. Adiabatic shearing band after post annealing was characterized by EBSD, which shows recrystallized grains with gradient diameters. In addition, it is found that the Burgers orientation relationship of the microStructure outside adiabatic shearing band was generally retained during the dynamic loading and post-annealing process.
C Zhao - One of the best experts on this subject based on the ideXlab platform.
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the yielding deformation and fracture behavior for the Widmanstatten Structure of ti 8al 1mo 1v alloy upon high speed impact
Journal of Alloys and Compounds, 2019Co-Authors: C Zhao, Z H Wang, J W Qiao, Y C WuAbstract:Abstract The yielding, deformation and fracture behavior for the Widmanstatten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact were studied through characterization and discussion. Seven strain rates ranging from 870 s−1 to 3300 s−1 were applied. The results show that: The yield strength of Widmanstatten Structure shows two distinct changing stages among the whole range of strain rates. Under the strain rates below 2250 s−1, Widmanstatten Structure exhibits positive strain rate sensitivity. Surprisingly, under the strain rates from 2250 s−1 to 3300 s−1, it shows negative strain rate sensitivity. The increasing importance of twinning in the initiation of plastic deformation with higher strain rate is deemed as the reason causing this phenomenon. The dynamic compression behavior of Widmanstatten Structure is described by J-C model, which shows unstable prediction performance. Adiabatic shearing band starts forming under the strain rates above 1950 s−1, from which the fracture behavior of Widmanstatten Structure is analyzed. An interesting phenomenon is that the adiabatic shearing band thicknesses at different locations of specimen can be obviously different. This is attributed to the relative orientation of α lamellae to the biggest shear stress plane. Saw-tooth chips start forming at the two end faces of specimen under the strain rates above 2500 s−1, and its formation mechanism is thoroughly discussed. Adiabatic shearing band after post annealing was characterized by EBSD, which shows recrystallized grains with gradient diameters. In addition, it is found that the Burgers orientation relationship of the microStructure outside adiabatic shearing band was generally retained during the dynamic loading and post-annealing process.
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The yielding, deformation and fracture behavior for the Widmanstätten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact
Journal of Alloys and Compounds, 2019Co-Authors: C Zhao, Z H Wang, Junwei Qiao, Y C WuAbstract:Abstract The yielding, deformation and fracture behavior for the Widmanstatten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact were studied through characterization and discussion. Seven strain rates ranging from 870 s−1 to 3300 s−1 were applied. The results show that: The yield strength of Widmanstatten Structure shows two distinct changing stages among the whole range of strain rates. Under the strain rates below 2250 s−1, Widmanstatten Structure exhibits positive strain rate sensitivity. Surprisingly, under the strain rates from 2250 s−1 to 3300 s−1, it shows negative strain rate sensitivity. The increasing importance of twinning in the initiation of plastic deformation with higher strain rate is deemed as the reason causing this phenomenon. The dynamic compression behavior of Widmanstatten Structure is described by J-C model, which shows unstable prediction performance. Adiabatic shearing band starts forming under the strain rates above 1950 s−1, from which the fracture behavior of Widmanstatten Structure is analyzed. An interesting phenomenon is that the adiabatic shearing band thicknesses at different locations of specimen can be obviously different. This is attributed to the relative orientation of α lamellae to the biggest shear stress plane. Saw-tooth chips start forming at the two end faces of specimen under the strain rates above 2500 s−1, and its formation mechanism is thoroughly discussed. Adiabatic shearing band after post annealing was characterized by EBSD, which shows recrystallized grains with gradient diameters. In addition, it is found that the Burgers orientation relationship of the microStructure outside adiabatic shearing band was generally retained during the dynamic loading and post-annealing process.
S L Semiatin - One of the best experts on this subject based on the ideXlab platform.
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microStructure development and segment formation during eca pressing of ti 6al 4v alloy
Scripta Materialia, 2004Co-Authors: D H Shin, Young Gun Ko, S L SemiatinAbstract:Abstract The deformed microStructures of Ti–6Al–4V alloys with either equiaxed or Widmanstatten Structure processed by equal channel angular pressing at 600 °C were examined by transmission electron microscopy. It was shown that the slip system and the flow localization were dependent on the initial microStructures, which was discussed in relation with α/β interfaces.
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MicroStructure development and segment formation during ECA pressing of Ti–6Al–4V alloy
Scripta Materialia, 2004Co-Authors: D H Shin, Young Gun Ko, S L SemiatinAbstract:Abstract The deformed microStructures of Ti–6Al–4V alloys with either equiaxed or Widmanstatten Structure processed by equal channel angular pressing at 600 °C were examined by transmission electron microscopy. It was shown that the slip system and the flow localization were dependent on the initial microStructures, which was discussed in relation with α/β interfaces.
J. I. Goldstein - One of the best experts on this subject based on the ideXlab platform.
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the formation of the Widmanstatten Structure in meteorites
Meteoritics & Planetary Science, 2005Co-Authors: J Yang, J. I. GoldsteinAbstract:We have evaluated various mechanisms proposed for the formation of the Widmanstatten pattern in iron meteorites and propose a new mechanism for low P meteoritic metal. These mechanisms can also be used to explain how the metallic microStructures developed in chondrites and stony-iron meteorites. The Widmanstatten pattern in high P iron meteorites forms when meteorites enter the three- phase field α + γ + Ph via cooling from the γ + Ph field. The Widmanstatten pattern in low P iron meteorites forms either at a temperature below the (α + γ)/(α + γ + Ph) boundary or by the decomposition of martensite below the martensite start temperature. The reaction γ → α + γ, which is normally assumed to control the formation of the Widmanstatten pattern, is not applicable to the metal in meteorites. The formation of the Widmanstatten pattern in the vast majority of low P iron meteorites (which belong to chemical groups IAB-IIICD, IIIAB, and IVA) is controlled by mechanisms involving the formation of martensite α2. We propose that the Widmanstatten Structure in these meteorites forms by the reaction γ → α2 + γ → α + γ, in which α2 decomposes to the equilibrium α and γ phases during the cooling process. To determine the cooling rate of an individual iron meteorite, the appropriate formation mechanism for the Widmanstatten pattern must first be established. Depending on the Ni and P content of the meteorite, the kamacite nucleation temperature can be determined from either the (γ + Ph)/(α + γ + Ph) boundary, the (α + γ)/(α + γ + Ph) boundary, or the Ms temperature. With the introduction of these three mechanisms and the specific phase boundaries and the temperatures where transformations occur, it is no longer necessary to invoke arbitrary amounts of under-cooling in the calculation of the cooling rate. We conclude that martensite decomposition via the reactions γ → α2 → α + γ and γ → α2 + γ → α + γ are responsible for the formation of plessite in irons and the metal phases of mesosiderites, chondrites, and pallasites. The hexahedrites (low P members of chemical group IIAB) formed by the massive transformation through the reaction γ → αm → α at relatively high temperature in the two- phase α + γ region of the Fe-Ni-P phase diagram near the α/(α + γ) phase boundary.
Z H Wang - One of the best experts on this subject based on the ideXlab platform.
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the yielding deformation and fracture behavior for the Widmanstatten Structure of ti 8al 1mo 1v alloy upon high speed impact
Journal of Alloys and Compounds, 2019Co-Authors: C Zhao, Z H Wang, J W Qiao, Y C WuAbstract:Abstract The yielding, deformation and fracture behavior for the Widmanstatten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact were studied through characterization and discussion. Seven strain rates ranging from 870 s−1 to 3300 s−1 were applied. The results show that: The yield strength of Widmanstatten Structure shows two distinct changing stages among the whole range of strain rates. Under the strain rates below 2250 s−1, Widmanstatten Structure exhibits positive strain rate sensitivity. Surprisingly, under the strain rates from 2250 s−1 to 3300 s−1, it shows negative strain rate sensitivity. The increasing importance of twinning in the initiation of plastic deformation with higher strain rate is deemed as the reason causing this phenomenon. The dynamic compression behavior of Widmanstatten Structure is described by J-C model, which shows unstable prediction performance. Adiabatic shearing band starts forming under the strain rates above 1950 s−1, from which the fracture behavior of Widmanstatten Structure is analyzed. An interesting phenomenon is that the adiabatic shearing band thicknesses at different locations of specimen can be obviously different. This is attributed to the relative orientation of α lamellae to the biggest shear stress plane. Saw-tooth chips start forming at the two end faces of specimen under the strain rates above 2500 s−1, and its formation mechanism is thoroughly discussed. Adiabatic shearing band after post annealing was characterized by EBSD, which shows recrystallized grains with gradient diameters. In addition, it is found that the Burgers orientation relationship of the microStructure outside adiabatic shearing band was generally retained during the dynamic loading and post-annealing process.
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The yielding, deformation and fracture behavior for the Widmanstätten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact
Journal of Alloys and Compounds, 2019Co-Authors: C Zhao, Z H Wang, Junwei Qiao, Y C WuAbstract:Abstract The yielding, deformation and fracture behavior for the Widmanstatten Structure of Ti–8Al–1Mo–1V alloy upon high speed impact were studied through characterization and discussion. Seven strain rates ranging from 870 s−1 to 3300 s−1 were applied. The results show that: The yield strength of Widmanstatten Structure shows two distinct changing stages among the whole range of strain rates. Under the strain rates below 2250 s−1, Widmanstatten Structure exhibits positive strain rate sensitivity. Surprisingly, under the strain rates from 2250 s−1 to 3300 s−1, it shows negative strain rate sensitivity. The increasing importance of twinning in the initiation of plastic deformation with higher strain rate is deemed as the reason causing this phenomenon. The dynamic compression behavior of Widmanstatten Structure is described by J-C model, which shows unstable prediction performance. Adiabatic shearing band starts forming under the strain rates above 1950 s−1, from which the fracture behavior of Widmanstatten Structure is analyzed. An interesting phenomenon is that the adiabatic shearing band thicknesses at different locations of specimen can be obviously different. This is attributed to the relative orientation of α lamellae to the biggest shear stress plane. Saw-tooth chips start forming at the two end faces of specimen under the strain rates above 2500 s−1, and its formation mechanism is thoroughly discussed. Adiabatic shearing band after post annealing was characterized by EBSD, which shows recrystallized grains with gradient diameters. In addition, it is found that the Burgers orientation relationship of the microStructure outside adiabatic shearing band was generally retained during the dynamic loading and post-annealing process.