The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The co...The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The cold-rolled high-purity aluminum sheets were annealed for 60 min at 200,300 and 400℃,respectively with and without an external DC electric field of 800 V/mm.The results show that with DC electric field,the recrystallization cube texture is strengthened at the stage of grain growth. Possible reason for the strengthening of the recrystallization cube texture with the applied electric field may be attributed to both selected nucleation and selected growth of cube oriented crystal nuclei.展开更多
The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformati...The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformation modes. Cold-deformed texture was investigated. The results show that the texture character in pure copper processed by ECAP is related with intersection angle (Φ) of the die channel. When Φ is 90° and the sample is extruded for one pass, its texture consists of α and β orientation lines including mainly C, B, S and Goss components, moreover a little rotated cube is found. When Φ is 135°, as extrusion pass increases, the weak texture forms on the scope of deviation from rotated cube (ψ=0°, θ=0°,φ=450°±150°) and develops to the ψ=45° fiber mainly including rotated cube. When Φ is 120°, the texture is ψ=45° fiber mainly including rotated cube that is maintained constant as extrusion pass increases.展开更多
The recrystallization texture evolution in heavily cold-rolled （93%） FeCo-2V alloy with annealing temperature and time was investigated by X-ray diffraction and electron backscatter diffraction. It was found that th...The recrystallization texture evolution in heavily cold-rolled （93%） FeCo-2V alloy with annealing temperature and time was investigated by X-ray diffraction and electron backscatter diffraction. It was found that the orientation density of α-fiber texture component fluctuates with increasing annealing temperature and time. The transmission electron microscopy images show that abundant precipitates appear inside the recrystallized grains and around the grain boundaries. The amount and size of the precipitates also vary with annealing temperature and time. The enhancement of the α-fiber coincides well with the increase of number density of fine precipitates, indicating that the fine precipitates facilitate the development of α-fiber. The annealing texture evolution observed in the FeCo alloy could be attributed to the facilitating effect of the precipitates on the development of α-fiber and the ordering process.展开更多
High-energy synchrotron diffraction offers great potential for experimental study of recrystallization kinetics. An experimental design to study the recrystallization mechanism of interstitial-free （IF） steel was im...High-energy synchrotron diffraction offers great potential for experimental study of recrystallization kinetics. An experimental design to study the recrystallization mechanism of interstitial-free （IF） steel was implemented. The whole annealing process of cold-rolled IF steel with 80% reduction was observed in situ using high-energy X-ray diffraction （HEXRD）. The results show how the main texture component of IF steel change, i.e. the α [∥rolling direction （RD）] fiber texture decreases and the γ [∥normal direction （ND）] fiber texture increases. The important part of the α fiber texture is that both the {100} and {112} texture decrease at the beginning of recrystallization. The γ fiber texture increases at the early stage of recrystallization which stems from the increase of {111}. Nevertheless, the {111} does not change after recrystallization. The dynamic evolution of the main texture components {100}, {112}, {111} and {111} is given by in-situ HEXRD.展开更多
In this paper, the texture and microstructure evolution of drawn-torsion and drawn-annealing-torsion ferrite wires are studied by electron back scattering diffraction （EBSD） in order to investigate the special torsi...In this paper, the texture and microstructure evolution of drawn-torsion and drawn-annealing-torsion ferrite wires are studied by electron back scattering diffraction （EBSD） in order to investigate the special torsion texture evolution. Compared to the simulation results, the stable texture components {110}〈 110 〉 and {110}〈112〉 in both drawn-torsion and drawn-annealing-torsion wires display different evolution processes. The texture of the drawn-annealing-torsion wire fits to the Taylor model. A special texture evolution is found in drawn-torsion wires, related to the grain shape, and the heterogeneous deformation. A new plastic deformation viewpoint is suggested based on the special microstructure of drawn ferrite wire.展开更多
High energy synchrotron diffraction offers great potential to study the recrystallization kinetics of metallic materials. To study the formation of Goss texture （{ [10}（001）） of grain oriented （GO） silicon steel...High energy synchrotron diffraction offers great potential to study the recrystallization kinetics of metallic materials. To study the formation of Goss texture （{ [10}（001）） of grain oriented （GO） silicon steel during secondary recrystallization process, an in situ experiment using hi gh energy X-ray diffraction was designed. The results showed that the secondary recrystallization began when the heating temperature was 1,494 K, and the grains grew rapidly above this temperature. With an increase in annealing temperature, the large grains with 7 orientation [〈111〉//normal direction] formed and gradually occupied the dominant position. As the annealing temperature increased even further, the grains with Goss orientation to a very large size by devouring the 7 orientation grains that formed in the early annealing stage. A single crystal with a Goss orientation was observed in the GO silicon steel when the annealing temperature was 1,540 K.展开更多
基金Project(50374028)supported by the National Natural Science Foundation of China and Shanghai Bao Steel Group of ChinaProject(PRAMX04-02)supported by Sino-French Cooperation Program
文摘The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The cold-rolled high-purity aluminum sheets were annealed for 60 min at 200,300 and 400℃,respectively with and without an external DC electric field of 800 V/mm.The results show that with DC electric field,the recrystallization cube texture is strengthened at the stage of grain growth. Possible reason for the strengthening of the recrystallization cube texture with the applied electric field may be attributed to both selected nucleation and selected growth of cube oriented crystal nuclei.
基金Project(Lnzr0201) supported by the Foundation of Science and Technology Committee of Liaoning Province of China
文摘The commercially pure copper with dimension of 80 mm×20 mm×4 mm was used for equal channel angular pressing (ECAP), of which their outward appearance coordinate is corresponded with that of rolling deformation modes. Cold-deformed texture was investigated. The results show that the texture character in pure copper processed by ECAP is related with intersection angle (Φ) of the die channel. When Φ is 90° and the sample is extruded for one pass, its texture consists of α and β orientation lines including mainly C, B, S and Goss components, moreover a little rotated cube is found. When Φ is 135°, as extrusion pass increases, the weak texture forms on the scope of deviation from rotated cube (ψ=0°, θ=0°,φ=450°±150°) and develops to the ψ=45° fiber mainly including rotated cube. When Φ is 120°, the texture is ψ=45° fiber mainly including rotated cube that is maintained constant as extrusion pass increases.
基金support by the Na-tional Natural Science Foundation of China (Grant Nos.50471026 and 50725102) the Swedish Research Coun-cil in the frame of the SIDA project (Grant No. 348-2004-3475).
文摘The recrystallization texture evolution in heavily cold-rolled （93%） FeCo-2V alloy with annealing temperature and time was investigated by X-ray diffraction and electron backscatter diffraction. It was found that the orientation density of α-fiber texture component fluctuates with increasing annealing temperature and time. The transmission electron microscopy images show that abundant precipitates appear inside the recrystallized grains and around the grain boundaries. The amount and size of the precipitates also vary with annealing temperature and time. The enhancement of the α-fiber coincides well with the increase of number density of fine precipitates, indicating that the fine precipitates facilitate the development of α-fiber. The annealing texture evolution observed in the FeCo alloy could be attributed to the facilitating effect of the precipitates on the development of α-fiber and the ordering process.
基金Sponsored by Key Projects in National Science and Technology Pillar Program of China(2011BAE13B03)Fundamental Research Funds for Central Universities of China(N110502001)
文摘High-energy synchrotron diffraction offers great potential for experimental study of recrystallization kinetics. An experimental design to study the recrystallization mechanism of interstitial-free （IF） steel was implemented. The whole annealing process of cold-rolled IF steel with 80% reduction was observed in situ using high-energy X-ray diffraction （HEXRD）. The results show how the main texture component of IF steel change, i.e. the α [∥rolling direction （RD）] fiber texture decreases and the γ [∥normal direction （ND）] fiber texture increases. The important part of the α fiber texture is that both the {100} and {112} texture decrease at the beginning of recrystallization. The γ fiber texture increases at the early stage of recrystallization which stems from the increase of {111}. Nevertheless, the {111} does not change after recrystallization. The dynamic evolution of the main texture components {100}, {112}, {111} and {111} is given by in-situ HEXRD.
基金supported by Key Projects of the National Science&Technology Pillar Program(No.2011BAE13B03)the Fundamental Research Funds for the Central Universities(No.N110502001)
文摘In this paper, the texture and microstructure evolution of drawn-torsion and drawn-annealing-torsion ferrite wires are studied by electron back scattering diffraction （EBSD） in order to investigate the special torsion texture evolution. Compared to the simulation results, the stable texture components {110}〈 110 〉 and {110}〈112〉 in both drawn-torsion and drawn-annealing-torsion wires display different evolution processes. The texture of the drawn-annealing-torsion wire fits to the Taylor model. A special texture evolution is found in drawn-torsion wires, related to the grain shape, and the heterogeneous deformation. A new plastic deformation viewpoint is suggested based on the special microstructure of drawn ferrite wire.
基金supported by the Key Projects of the National Science & Technology Pillar Program (No. 2011BAE13B03)the Fundamental Research Funds for the Central Universities (No. N110502001)
文摘High energy synchrotron diffraction offers great potential to study the recrystallization kinetics of metallic materials. To study the formation of Goss texture （{ [10}（001）） of grain oriented （GO） silicon steel during secondary recrystallization process, an in situ experiment using hi gh energy X-ray diffraction was designed. The results showed that the secondary recrystallization began when the heating temperature was 1,494 K, and the grains grew rapidly above this temperature. With an increase in annealing temperature, the large grains with 7 orientation [〈111〉//normal direction] formed and gradually occupied the dominant position. As the annealing temperature increased even further, the grains with Goss orientation to a very large size by devouring the 7 orientation grains that formed in the early annealing stage. A single crystal with a Goss orientation was observed in the GO silicon steel when the annealing temperature was 1,540 K.
