The Experts below are selected from a list of 2811 Experts worldwide ranked by ideXlab platform
Sung Soo Park - One of the best experts on this subject based on the ideXlab platform.
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effect of the extrusion conditions on the texture and mechanical properties of indirect extruded mg 3al 1zn alloy
Journal of Materials Processing Technology, 2009Co-Authors: Sung Soo Park, Dukjae YoonAbstract:Abstract The effects of the processing conditions on the texture and mechanical properties of indirect-extruded Mg–3Al–1Zn alloy are investigated. During the extrusion process, the alloy was subjected to various initial billet temperatures and ram speeds, exhibiting different extrudate exit temperatures depending on the extrusion conditions. The Zener-Hollomon Parameter acquired from the exit temperature of the extrudate and the ram speed was found to have a significant effect on the grain size, texture, and yield asymmetry of the extruded alloy. Among the processing conditions investigated, a higher Zener-Hollomon Parameter resulted in a finer grain size and weaker fiber texture, thereby decreasing the yield asymmetry of the extruded Mg alloy.
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Effect of the extrusion conditions on the texture and mechanical properties of indirect-extruded Mg–3Al–1Zn alloy
Journal of Materials Processing Technology, 2009Co-Authors: Sung Soo Park, B.s. You, Dukjae YoonAbstract:Abstract The effects of the processing conditions on the texture and mechanical properties of indirect-extruded Mg–3Al–1Zn alloy are investigated. During the extrusion process, the alloy was subjected to various initial billet temperatures and ram speeds, exhibiting different extrudate exit temperatures depending on the extrusion conditions. The Zener-Hollomon Parameter acquired from the exit temperature of the extrudate and the ram speed was found to have a significant effect on the grain size, texture, and yield asymmetry of the extruded alloy. Among the processing conditions investigated, a higher Zener-Hollomon Parameter resulted in a finer grain size and weaker fiber texture, thereby decreasing the yield asymmetry of the extruded Mg alloy.
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Effect of the extrusion conditions on the texture and mechanical properties of indirect-extruded Mg–3Al–1Zn alloy
Journal of Materials Processing Technology, 2009Co-Authors: Sung Soo Park, B.s. You, D.j. YoonAbstract:The effects of the processing conditions on the texture and mechanical properties of indirect-extruded Mg-3Al-1Zn alloy are investigated. During the extrusion process, the alloy was subjected to various initial billet temperatures and ram speeds, exhibiting different extrudate exit temperatures depending on the extrusion conditions. The Zener-Hollomon Parameter acquired from the exit temperature of the extrudate and the ram speed was found to have a significant effect on the grain size, texture, and yield asymmetry of the extruded alloy. Among the processing conditions investigated, a higher Zener-Hollomon Parameter resulted in a finer grain size and weaker fiber texture, thereby decreasing the yield asymmetry of the extruded Mg alloy.close464
Dukjae Yoon - One of the best experts on this subject based on the ideXlab platform.
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effect of the extrusion conditions on the texture and mechanical properties of indirect extruded mg 3al 1zn alloy
Journal of Materials Processing Technology, 2009Co-Authors: Sung Soo Park, Dukjae YoonAbstract:Abstract The effects of the processing conditions on the texture and mechanical properties of indirect-extruded Mg–3Al–1Zn alloy are investigated. During the extrusion process, the alloy was subjected to various initial billet temperatures and ram speeds, exhibiting different extrudate exit temperatures depending on the extrusion conditions. The Zener-Hollomon Parameter acquired from the exit temperature of the extrudate and the ram speed was found to have a significant effect on the grain size, texture, and yield asymmetry of the extruded alloy. Among the processing conditions investigated, a higher Zener-Hollomon Parameter resulted in a finer grain size and weaker fiber texture, thereby decreasing the yield asymmetry of the extruded Mg alloy.
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Effect of the extrusion conditions on the texture and mechanical properties of indirect-extruded Mg–3Al–1Zn alloy
Journal of Materials Processing Technology, 2009Co-Authors: Sung Soo Park, B.s. You, Dukjae YoonAbstract:Abstract The effects of the processing conditions on the texture and mechanical properties of indirect-extruded Mg–3Al–1Zn alloy are investigated. During the extrusion process, the alloy was subjected to various initial billet temperatures and ram speeds, exhibiting different extrudate exit temperatures depending on the extrusion conditions. The Zener-Hollomon Parameter acquired from the exit temperature of the extrudate and the ram speed was found to have a significant effect on the grain size, texture, and yield asymmetry of the extruded alloy. Among the processing conditions investigated, a higher Zener-Hollomon Parameter resulted in a finer grain size and weaker fiber texture, thereby decreasing the yield asymmetry of the extruded Mg alloy.
Partha Ghosal - One of the best experts on this subject based on the ideXlab platform.
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Dynamic recrystallization of a β(B2)-Stabilized γ-TiAl based Ti–45Al–8Nb–2Cr-0.2B alloy: The contributions of constituent phases and Zener-Hollomon Parameter modulated recrystallization mechanisms
Journal of Alloys and Compounds, 2020Co-Authors: Vajinder Singh, Chandan Mondal, Rajdeep Sarkar, Pinaki Prasad Bhattacharjee, Partha GhosalAbstract:Abstract Dynamic recrystallization (DRX) behavior of a high Nb-containing cast γ-TiAl based Ti–45Al–8Nb–2Cr-0.2B (at.%) alloy has been studied during hot compressive deformation in the temperature range of 1000–1200 °C and the strain rate range of 0.5–0.005 s−1. Detailed microstructural evolution in conjunction with flow curve analysis suggests that flow softening is associated with differential DRX behavior of the constituent phases as well as deformation instability. Such differential DRX of constituent phases leads to a considerable departure from the power-law dependence of the critical stress (σc) and strain (ec) Parameters derived through the Poliak-Jonas analytical methodology. Further analysis of the kinetics of flow softening by the modified Avrami type Arrhenius equation indicates that the strain rate strongly influences the Avrami constants. The resultant curves of DRX kinetics predict a characteristic “C”-shape instead of the sigmoidal-shape presumably due to a flow instability facilitated by the differential contribution of constituent phases. Detailed characterization of microstructural evolution as a function of the Zener-Hollomon Parameter (Z) is further augmented through phase-resolved sub-grain structures, misorientation (KAM) maps, and recrystallized grains evaluation by EBSD technique. The analyses in corroboration with transmission electron microscopy suggest that discontinuous dynamic recrystallization (DDRX) dominates at the high Z condition leading a fine and homogeneous grain structure. At lower Z conditions, on the other hand, a broad spectrum of recrystallized grain size distribution is developed as a result of a combination of DDRX and CDRX processes.
Vajinder Singh - One of the best experts on this subject based on the ideXlab platform.
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Dynamic recrystallization of a β(B2)-Stabilized γ-TiAl based Ti–45Al–8Nb–2Cr-0.2B alloy: The contributions of constituent phases and Zener-Hollomon Parameter modulated recrystallization mechanisms
Journal of Alloys and Compounds, 2020Co-Authors: Vajinder Singh, Chandan Mondal, Rajdeep Sarkar, Pinaki Prasad Bhattacharjee, Partha GhosalAbstract:Abstract Dynamic recrystallization (DRX) behavior of a high Nb-containing cast γ-TiAl based Ti–45Al–8Nb–2Cr-0.2B (at.%) alloy has been studied during hot compressive deformation in the temperature range of 1000–1200 °C and the strain rate range of 0.5–0.005 s−1. Detailed microstructural evolution in conjunction with flow curve analysis suggests that flow softening is associated with differential DRX behavior of the constituent phases as well as deformation instability. Such differential DRX of constituent phases leads to a considerable departure from the power-law dependence of the critical stress (σc) and strain (ec) Parameters derived through the Poliak-Jonas analytical methodology. Further analysis of the kinetics of flow softening by the modified Avrami type Arrhenius equation indicates that the strain rate strongly influences the Avrami constants. The resultant curves of DRX kinetics predict a characteristic “C”-shape instead of the sigmoidal-shape presumably due to a flow instability facilitated by the differential contribution of constituent phases. Detailed characterization of microstructural evolution as a function of the Zener-Hollomon Parameter (Z) is further augmented through phase-resolved sub-grain structures, misorientation (KAM) maps, and recrystallized grains evaluation by EBSD technique. The analyses in corroboration with transmission electron microscopy suggest that discontinuous dynamic recrystallization (DDRX) dominates at the high Z condition leading a fine and homogeneous grain structure. At lower Z conditions, on the other hand, a broad spectrum of recrystallized grain size distribution is developed as a result of a combination of DDRX and CDRX processes.
David Porter - One of the best experts on this subject based on the ideXlab platform.
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dynamic restoration mechanisms in a ti nb stabilized ferritic stainless steel during hot deformation
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2014Co-Authors: Saara Mehtonen, E J Palmiere, R D K Misra, L P Karjalainen, David PorterAbstract:Abstract The effect of strain and deformation conditions on the microstructure and texture evolution of a 21% Cr Ti–Nb stabilized ferritic stainless steel was investigated in order to identify the dynamic restoration mechanisms taking place during high temperature deformation. Plane strain hot compression tests were carried out at 950 and 1050 °C at strain rates of 0.1 s −1 and 10 s −1 to the true strains of 0.2, 0.5, 1 and 1.5. The deformed specimens were examined using electron backscatter diffraction and transmission electron microscopy. The microstructure and texture development depended on the deformation conditions. Under the highest Zener–Hollomon Parameter (8.91×10 17 s −1 ) the restoration mechanism was dynamic recovery. However, at the highest strain of 1.5, continuous dynamic recrystallization and geometric dynamic recrystallization occurred, whereas under the lowest Zener–Hollomon Parameter (4.67×10 14 s −1 ) the initiation of continuous dynamic recrystallization was observed at 0.2 strain and dynamically recrystallized grains were detected already at the strain of 1. The size of subgrains decreased with increasing strain and increasing Zener–Hollomon Parameter, and the stage at which a steady state was achieved, varied depending on the Zener–Hollomon Parameter. Intense dynamic recovery and continuous dynamic recrystallization under plane strain deformation conditions were found to lead to the formation of intense α and e fiber textures with a very weak γ fiber. Further, the possibility for the occurrence of discontinuous dynamic recrystallization is discussed.
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hot deformation behavior and microstructure evolution of a stabilized high cr ferritic stainless steel
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: Saara Mehtonen, L P Karjalainen, David PorterAbstract:Abstract The hot deformation behavior and static microstructure evolution of a 21Cr stabilized ferritic stainless steel was studied using axisymmetric hot compression tests on a Gleeble 1500 thermomechanical simulator. The deformation was carried out at 950–1050 °C to strains of 0.2 to 0.6 using strain rates of 0.01, 0.1 and 1 s −1 . The compression was followed by a holding period of 0 to 180 s in order to study the static recrystallization kinetics. The electron backscatter diffraction (EBSD) technique was used in analyzing the resultant microstructures. A constitutive equation that well describes the flow stress as a function of strain, strain rate and temperature was developed. The active dynamic restoration mechanism was found to depend on the Zener–Hollomon Parameter, such that continuous dynamic recrystallization was observed under low Zener–Hollomon Parameter conditions but under high Zener–Hollomon Parameter microstructures were dynamically recovered, and no dynamic formation of new grains occurred. Static recrystallization resulted in little or no grain refinement, and further, strain did not have an accelerating effect on the static recrystallization kinetics beyond the strain of 0.4.
