The Experts below are selected from a list of 297 Experts worldwide ranked by ideXlab platform
Xiaoxu Huang - One of the best experts on this subject based on the ideXlab platform.
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Grain Orientation dependence of deformation twinning in pure cu subjected to dynamic plastic deformation
Scripta Materialia, 2009Co-Authors: C S Hong, K Lu, Xiaoxu HuangAbstract:A clear Grain Orientation dependence of deformation twinning has been identified in coarse-Grained copper subjected to dynamic plastic deformation. Deformation twins tend to occur in Grains with Orientations near the [0 0 1] corner but not in Grains near the [1 0 1] corner, which can be explained in terms of a Schmid factor analysis. This finding provides a guideline for the design of initial texture in exploring the structural refinement via deformation twins. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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Grain Orientation deformation microstructure and flow stress
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008Co-Authors: Niels Hansen, Xiaoxu Huang, Grethe WintherAbstract:Dislocation structures in deformed metals have been analyzed quantitatively by transmission electron microscopy, high-resolution electron microscopy and Kikuchi line analysis. A general pattern for the microstructural evolution with increasing strain has been established and structural parameters have been defined and quantified. It has been found that two dislocation patterns co-exist in all Grains, however, with very different characteristics dependent on Grain Orientation. This correlation with the Grain Orientation has been applied in modeling of the tensile flow stress and the flow stress anisotropy of fcc polycrystals. In conclusion some future research areas are briefly outlined.
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dislocation structures part i Grain Orientation dependence
Philosophical Magazine, 2007Co-Authors: Xiaoxu Huang, Grethe WintherAbstract:To clarify the effect of Grain Orientation on the evolution of dislocation structures in metals of medium-to-high stacking fault energy, detailed TEM characterization of structures was carried out for more than 350 individual Grains in Al and Cu deformed in tension or by cold rolling up to moderate strain levels (ϵvM ≤ 0.8). Efforts were made to obtain a precise description of the three-dimensional arrangement of the dislocation structures and to determine the crystallographic plane of extended dislocation boundaries (geometrically necessary boundaries). A universal pattern of structural evolution characterized by a formation of three types of structure was found in both metals, irrespective of material parameters (stacking fault energy, Grain size and impurity) and deformation conditions (deformation mode, strain and strain rate). The key parameter controlling the formation of the different structural types was found to be Grain Orientation with respect to the deformation axis (axes) and a clear relation...
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Grain Orientation and Dislocation Patterns
Philosophical Magazine, 2006Co-Authors: Niels Hansen, Xiaoxu Huang, Wolfgang Pantleon, Grethe WintherAbstract:Dislocation patterns have been characterized by transmission electron microscopy and Kikuchi line analysis in pure, polycrystalline aluminium deformed in tension at room temperature in the strain range 0.05-0.34. The angular strain relationship of the dislocation boundaries, their scaling behaviour and the occurrence of similitude shows that two dislocation patterns coexist in all Grains, however, with very different characteristics dependent on the Grain Orientation. An analysis of the hardening behaviour of the Grains in the polycrystal and a comparison with single crystal behaviour show a similar strong correlation pointing to the slip pattern as a dominating factor both behind the microstructural evolution and the hardening. An analysis of operating slip systems has underpinned the division of the stereographic triangle based on the microstructural characterization and the hardening behaviour.
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Grain Orientation and Dislocation Patterns
Philosophical Magazine, 2006Co-Authors: Niels Hansen, Xiaoxu Huang, Wolfgang Pantleon, Grethe WintherAbstract:Dislocation patterns have been characterized by transmission electron microscopy and Kikuchi line analysis in pure, polycrystalline aluminium deformed in tension at room temperature in the strain range 0.05–0.34. The angle strain relationship of the dislocation boundaries, their scaling behaviour and the occurrence of similitude show that two dislocation patterns coexist in all Grains, albeit, with very different characteristics, dependent on the Grain Orientation. An analysis of the hardening behaviour of the Grains in the polycrystal and a comparison with single crystal behaviour show a similar strong correlation, pointing to the slip pattern as a dominating factor both behind the microstructural evolution and the hardening. The division of the stereographic triangle representing all possible crystallographic Orientations at the tensile axis based on microstructural characterization and hardening behaviour, correlates with a division based on slip pattern characteristics.
Jian Ku Shang - One of the best experts on this subject based on the ideXlab platform.
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dependence of electromigration damage on sn Grain Orientation in sn ag cu solder joints
Journal of Applied Physics, 2013Co-Authors: Jian Qiang Chen, Jian Ku ShangAbstract:The relationship between the “polarity effect” of electromigration on interfacial intermetallic growth and the Sn Grain Orientation was investigated in Sn-Ag-Cu solder joints. The growth of the interfacial intermetallic compound was found to depend strongly on the Sn Grain Orientation. When the c-axes of the Sn Grains were closely aligned to the current flow direction, a severe polarity effect was observed in which the anode interface was covered with a thick layer of Cu-Sn intermetallic while the intermetallic layer at the cathode interface was almost depleted. If the c-axes of the Sn Grains were rotated away from the current direction, the polarity effect became less pronounced. When the c-axis was perpendicular to the current direction, the polarity effect essentially disappeared. The difference in the intermetallic layer thickness between the anode and the cathode, Δd, followed a parabolic function of the cosine of the angle, α, between the c-axis and the current direction. A kinetic model based on th...
Niels Hansen - One of the best experts on this subject based on the ideXlab platform.
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Grain Orientation deformation microstructure and flow stress
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008Co-Authors: Niels Hansen, Xiaoxu Huang, Grethe WintherAbstract:Dislocation structures in deformed metals have been analyzed quantitatively by transmission electron microscopy, high-resolution electron microscopy and Kikuchi line analysis. A general pattern for the microstructural evolution with increasing strain has been established and structural parameters have been defined and quantified. It has been found that two dislocation patterns co-exist in all Grains, however, with very different characteristics dependent on Grain Orientation. This correlation with the Grain Orientation has been applied in modeling of the tensile flow stress and the flow stress anisotropy of fcc polycrystals. In conclusion some future research areas are briefly outlined.
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Grain Orientation and Dislocation Patterns
Philosophical Magazine, 2006Co-Authors: Niels Hansen, Xiaoxu Huang, Wolfgang Pantleon, Grethe WintherAbstract:Dislocation patterns have been characterized by transmission electron microscopy and Kikuchi line analysis in pure, polycrystalline aluminium deformed in tension at room temperature in the strain range 0.05-0.34. The angular strain relationship of the dislocation boundaries, their scaling behaviour and the occurrence of similitude shows that two dislocation patterns coexist in all Grains, however, with very different characteristics dependent on the Grain Orientation. An analysis of the hardening behaviour of the Grains in the polycrystal and a comparison with single crystal behaviour show a similar strong correlation pointing to the slip pattern as a dominating factor both behind the microstructural evolution and the hardening. An analysis of operating slip systems has underpinned the division of the stereographic triangle based on the microstructural characterization and the hardening behaviour.
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Grain Orientation and Dislocation Patterns
Philosophical Magazine, 2006Co-Authors: Niels Hansen, Xiaoxu Huang, Wolfgang Pantleon, Grethe WintherAbstract:Dislocation patterns have been characterized by transmission electron microscopy and Kikuchi line analysis in pure, polycrystalline aluminium deformed in tension at room temperature in the strain range 0.05–0.34. The angle strain relationship of the dislocation boundaries, their scaling behaviour and the occurrence of similitude show that two dislocation patterns coexist in all Grains, albeit, with very different characteristics, dependent on the Grain Orientation. An analysis of the hardening behaviour of the Grains in the polycrystal and a comparison with single crystal behaviour show a similar strong correlation, pointing to the slip pattern as a dominating factor both behind the microstructural evolution and the hardening. The division of the stereographic triangle representing all possible crystallographic Orientations at the tensile axis based on microstructural characterization and hardening behaviour, correlates with a division based on slip pattern characteristics.
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Effect of Grain Orientation on microstructures of aluminium in warm tension
Materials Science and Technology, 2005Co-Authors: Y. He, Niels Hansen, Xiaoxu Huang, Grethe WintherAbstract:AbstractThe dislocation structure in aluminium (AA1050) has been investigated after tension at 300°C (∼0·6T M) at a strain rate of 0·1 s−1 to a true strain of 0·15. The Grain Orientation dependence of the morphology and of the crystallographic planes of extended planar dislocation boundaries is similar to cold tension. It is demonstrated that crystallography has a stronger influence than the macroscopic stress on the boundary plane. Effects of strain and temperature increases are briefly illustrated and discussed.
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Grain Orientation dependence of microstructures in a warm rolled IF steel
Acta Materialia, 2004Co-Authors: Arunansu Haldar, Xiaoxu Huang, Torben Leffers, Niels HansenAbstract:The microstructures of an IF steel warm rolled to 10% and 30% reductions have been characterised by transmission electron microscopy. Individual Grains of various Orientations, namely {gamma} Grains within 15 deg of the {gamma} fibre ( //ND), {alpha} Grains within 15 deg of the {alpha} fibre ( //RD) and R Grains with Orientations other than {gamma} or {alpha} Grains, have been analysed. A common microstructural feature observed in all the Grains studied is the development of a cell block structure where cell blocks are delineated by extended planar dislocation boundaries. However, the characteristics of the boundaries depend on the Grain Orientation. The extended dislocation boundaries preferentially form on or close (mostly within 10 deg.) to the {l_brace}1 1 0{r_brace} and {l_brace}1 1 2{r_brace} active slip planes and they also have macroscopic Orientation with respect to the sample axes angles. The mean macroscopic angles are found to depend on the Grain Orientation. The large deviation of measured macroscopic angles (34 deg and -36 deg ) from the maximum shear plane Orientations ({+-}45 deg ) observed in the {gamma} and {alpha} Grains, and similar observations reported in the literature can be related to a strong correlation between the planes ofmore » the extended dislocation boundaries and the active slip planes.« less
Grethe Winther - One of the best experts on this subject based on the ideXlab platform.
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Grain Orientation dependence of extended planar dislocation boundaries in rolled aluminium
Scripta Materialia, 2009Co-Authors: Andrew Godfrey, Grethe WintherAbstract:The dislocation boundary alignment in 124 Grains in cold-rolled aluminium has been investigated by a combination of backscattered electron channelling contrast and electron backscatter diffraction. The asymmetric slip geometry of the Copper and S Orientations together with the existence of different symmetry variants of these Orientations is exploited to analyse whether the Grain Orientation (and consequently the slip systems) or the symmetric rolling geometry determines the boundary alignment. The results unambiguously point at the Grain Orientation as the controlling factor.
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Grain Orientation deformation microstructure and flow stress
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008Co-Authors: Niels Hansen, Xiaoxu Huang, Grethe WintherAbstract:Dislocation structures in deformed metals have been analyzed quantitatively by transmission electron microscopy, high-resolution electron microscopy and Kikuchi line analysis. A general pattern for the microstructural evolution with increasing strain has been established and structural parameters have been defined and quantified. It has been found that two dislocation patterns co-exist in all Grains, however, with very different characteristics dependent on Grain Orientation. This correlation with the Grain Orientation has been applied in modeling of the tensile flow stress and the flow stress anisotropy of fcc polycrystals. In conclusion some future research areas are briefly outlined.
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dislocation structures part i Grain Orientation dependence
Philosophical Magazine, 2007Co-Authors: Xiaoxu Huang, Grethe WintherAbstract:To clarify the effect of Grain Orientation on the evolution of dislocation structures in metals of medium-to-high stacking fault energy, detailed TEM characterization of structures was carried out for more than 350 individual Grains in Al and Cu deformed in tension or by cold rolling up to moderate strain levels (ϵvM ≤ 0.8). Efforts were made to obtain a precise description of the three-dimensional arrangement of the dislocation structures and to determine the crystallographic plane of extended dislocation boundaries (geometrically necessary boundaries). A universal pattern of structural evolution characterized by a formation of three types of structure was found in both metals, irrespective of material parameters (stacking fault energy, Grain size and impurity) and deformation conditions (deformation mode, strain and strain rate). The key parameter controlling the formation of the different structural types was found to be Grain Orientation with respect to the deformation axis (axes) and a clear relation...
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Grain Orientation and Dislocation Patterns
Philosophical Magazine, 2006Co-Authors: Niels Hansen, Xiaoxu Huang, Wolfgang Pantleon, Grethe WintherAbstract:Dislocation patterns have been characterized by transmission electron microscopy and Kikuchi line analysis in pure, polycrystalline aluminium deformed in tension at room temperature in the strain range 0.05-0.34. The angular strain relationship of the dislocation boundaries, their scaling behaviour and the occurrence of similitude shows that two dislocation patterns coexist in all Grains, however, with very different characteristics dependent on the Grain Orientation. An analysis of the hardening behaviour of the Grains in the polycrystal and a comparison with single crystal behaviour show a similar strong correlation pointing to the slip pattern as a dominating factor both behind the microstructural evolution and the hardening. An analysis of operating slip systems has underpinned the division of the stereographic triangle based on the microstructural characterization and the hardening behaviour.
-
Grain Orientation and Dislocation Patterns
Philosophical Magazine, 2006Co-Authors: Niels Hansen, Xiaoxu Huang, Wolfgang Pantleon, Grethe WintherAbstract:Dislocation patterns have been characterized by transmission electron microscopy and Kikuchi line analysis in pure, polycrystalline aluminium deformed in tension at room temperature in the strain range 0.05–0.34. The angle strain relationship of the dislocation boundaries, their scaling behaviour and the occurrence of similitude show that two dislocation patterns coexist in all Grains, albeit, with very different characteristics, dependent on the Grain Orientation. An analysis of the hardening behaviour of the Grains in the polycrystal and a comparison with single crystal behaviour show a similar strong correlation, pointing to the slip pattern as a dominating factor both behind the microstructural evolution and the hardening. The division of the stereographic triangle representing all possible crystallographic Orientations at the tensile axis based on microstructural characterization and hardening behaviour, correlates with a division based on slip pattern characteristics.
Jian Qiang Chen - One of the best experts on this subject based on the ideXlab platform.
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dependence of electromigration damage on sn Grain Orientation in sn ag cu solder joints
Journal of Applied Physics, 2013Co-Authors: Jian Qiang Chen, Jian Ku ShangAbstract:The relationship between the “polarity effect” of electromigration on interfacial intermetallic growth and the Sn Grain Orientation was investigated in Sn-Ag-Cu solder joints. The growth of the interfacial intermetallic compound was found to depend strongly on the Sn Grain Orientation. When the c-axes of the Sn Grains were closely aligned to the current flow direction, a severe polarity effect was observed in which the anode interface was covered with a thick layer of Cu-Sn intermetallic while the intermetallic layer at the cathode interface was almost depleted. If the c-axes of the Sn Grains were rotated away from the current direction, the polarity effect became less pronounced. When the c-axis was perpendicular to the current direction, the polarity effect essentially disappeared. The difference in the intermetallic layer thickness between the anode and the cathode, Δd, followed a parabolic function of the cosine of the angle, α, between the c-axis and the current direction. A kinetic model based on th...
