The Experts below are selected from a list of 1842 Experts worldwide ranked by ideXlab platform
Jiecai Han - One of the best experts on this subject based on the ideXlab platform.
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the ideal strength of transition metal diborides tmb2 tm ti zr hf plastic anisotropy and the role of Prismatic Slip
Scripta Materialia, 2010Co-Authors: Xinghong Zhang, Xiaoguang Luo, Jiecai HanAbstract:The ideal tensile and shear strengths of TiB 2 , ZrB 2 and HfB 2 have been investigated by first-principles stress–strain calculations. Among the studied diborides, TiB 2 unexpectedly exhibits the weakest shear strength in the (0 0 0 1) basal plane, comparable to that of ZrB 2 and HfB 2 in the { 1 0 1 ¯ 0 } Prismatic planes. Due to the nonlinearity of the stress response at large stains, the plastic anisotropy cannot be derived from elastic constants. Based on the relative stiffness of boron hexagons, a bond length indicator is obtained to characterize the preference for basal or Prismatic Slip in diborides.
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The ideal strength of transition metal diborides TMB2 (TM = Ti, Zr, Hf): Plastic anisotropy and the role of Prismatic Slip
Scripta Materialia, 2010Co-Authors: Xinghong Zhang, Xiaoguang Luo, Jiecai HanAbstract:The ideal tensile and shear strengths of TiB 2 , ZrB 2 and HfB 2 have been investigated by first-principles stress–strain calculations. Among the studied diborides, TiB 2 unexpectedly exhibits the weakest shear strength in the (0 0 0 1) basal plane, comparable to that of ZrB 2 and HfB 2 in the { 1 0 1 ¯ 0 } Prismatic planes. Due to the nonlinearity of the stress response at large stains, the plastic anisotropy cannot be derived from elastic constants. Based on the relative stiffness of boron hexagons, a bond length indicator is obtained to characterize the preference for basal or Prismatic Slip in diborides.
Wenbin Guo - One of the best experts on this subject based on the ideXlab platform.
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the formation mechanism between the 101 2 twins and Prismatic Slip on 101 0 plane application to zircaloy 4 alloy
Materials Chemistry and Physics, 2020Co-Authors: Yingdong Zhang, Fusen Yuan, Fuzhou Han, Muhammad Ubaid Ali, Wenbin GuoAbstract:Abstract The formation mechanism between {10 1 ‾ 2} twins (TWs) and Prismatic Slip (PR) in the Zircaloy-4 alloy was investigated by the situ study of Transmission Kikuchi Diffraction (TKD) as well as transmission electron microscope (TEM) methods. Our results reveal that the PR and TWs were easily formed on the (10 1 ‾ 0) plane, due to the high Schmid factor values of PR (0.46) and TWs (0.5) were caused by the compression force (CF) – F(30, 90). Moreover, the relationship between CF and driving force (DF) of PR was got as DF = CFcos30°.
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The formation mechanism between the {101‾2} twins and Prismatic Slip on (101‾0) plane: Application to Zircaloy-4 alloy
Materials Chemistry and Physics, 2020Co-Authors: Yingdong Zhang, Fusen Yuan, Fuzhou Han, Muhammad Ubaid Ali, Wenbin Guo, Chengze LiuAbstract:Abstract The formation mechanism between {10 1 ‾ 2} twins (TWs) and Prismatic Slip (PR) in the Zircaloy-4 alloy was investigated by the situ study of Transmission Kikuchi Diffraction (TKD) as well as transmission electron microscope (TEM) methods. Our results reveal that the PR and TWs were easily formed on the (10 1 ‾ 0) plane, due to the high Schmid factor values of PR (0.46) and TWs (0.5) were caused by the compression force (CF) – F(30, 90). Moreover, the relationship between CF and driving force (DF) of PR was got as DF = CFcos30°.
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Anisotropic yielding behavior and associated mechanism of cold rolled and annealed Zircaloy-4 alloy thin sheets under tensile condition
Materials Chemistry and Physics, 2020Co-Authors: Fuzhou Han, Yingdong Zhang, Fusen Yuan, Muhammad Ubaid Ali, Chengze Liu, Wenbin GuoAbstract:Abstract The significant yielding anisotropy of cold rolled and annealed Zircaloy-4 (Zr-4) alloy thin sheets was investigated by performing uniaxial tensile tests along the two typical directions, the rolling direction (RD) and transverse direction (TD). The associated deformation mechanism was determined by the combined analysis of critical resolved shear stress (CRSS) and calculated Schmid Factor (SF) value that dependent on crystallographic texture. Prismatic Slip was demonstrated to be the dominant deformation mechanism for the material yielding. Results revealed that the specific crystallographic orientation of the Zr-4 alloy caused by rolling texture, influences the activities of Prismatic Slip by affecting their SF, which was depending on the geometric relationship between loading direction and crystallography, thereby leading to the anisotropic deformation. Quantitative analysis of this dominant deformation mode showed that the variety of Prismatic Slip activity with the loading direction gave rise to the yielding anisotropy of Zr-4 alloy sheets under tensile condition.
Xinghong Zhang - One of the best experts on this subject based on the ideXlab platform.
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the ideal strength of transition metal diborides tmb2 tm ti zr hf plastic anisotropy and the role of Prismatic Slip
Scripta Materialia, 2010Co-Authors: Xinghong Zhang, Xiaoguang Luo, Jiecai HanAbstract:The ideal tensile and shear strengths of TiB 2 , ZrB 2 and HfB 2 have been investigated by first-principles stress–strain calculations. Among the studied diborides, TiB 2 unexpectedly exhibits the weakest shear strength in the (0 0 0 1) basal plane, comparable to that of ZrB 2 and HfB 2 in the { 1 0 1 ¯ 0 } Prismatic planes. Due to the nonlinearity of the stress response at large stains, the plastic anisotropy cannot be derived from elastic constants. Based on the relative stiffness of boron hexagons, a bond length indicator is obtained to characterize the preference for basal or Prismatic Slip in diborides.
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The ideal strength of transition metal diborides TMB2 (TM = Ti, Zr, Hf): Plastic anisotropy and the role of Prismatic Slip
Scripta Materialia, 2010Co-Authors: Xinghong Zhang, Xiaoguang Luo, Jiecai HanAbstract:The ideal tensile and shear strengths of TiB 2 , ZrB 2 and HfB 2 have been investigated by first-principles stress–strain calculations. Among the studied diborides, TiB 2 unexpectedly exhibits the weakest shear strength in the (0 0 0 1) basal plane, comparable to that of ZrB 2 and HfB 2 in the { 1 0 1 ¯ 0 } Prismatic planes. Due to the nonlinearity of the stress response at large stains, the plastic anisotropy cannot be derived from elastic constants. Based on the relative stiffness of boron hexagons, a bond length indicator is obtained to characterize the preference for basal or Prismatic Slip in diborides.
Matthew Barnett - One of the best experts on this subject based on the ideXlab platform.
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solute strengthening of Prismatic Slip basal Slip and 1 0 1 2 twinning in mg and mg zn binary alloys
International Journal of Plasticity, 2013Co-Authors: Nicole Stanford, Matthew BarnettAbstract:Abstract Mg–Zn binary alloys with concentrations between 0 and 2.8 wt% Zn have been prepared and processed via hot rolling and annealing to produce specimens with a strong basal texture and a range of grain sizes. These have been deformed in three different strain paths: tension, compression and shear, in order to promote the dominance of Prismatic Slip, { 1 0 1 ¯ 2 } twinning and basal Slip, respectively. This experimental data has been used to create Hall–Petch plots for each deformation mode. It has been found that the Prismatic Slip system has a plateau in its Hall–Petch plot above grain sizes of ∼30 μm, and solute softening of the Prismatic system was found to be operative only at grain sizes above ∼50 μm. In compression, the stress required to activate twinning was found to be insensitive to Zn concentration. It is proposed that solute softening and anomalous Hall–Petch behaviour of Prismatic Slip be understood in terms of the dominance of the cross-Slip stress in coarse grained materials. The effect of grain size on the relative strength of basal Slip, Prismatic Slip and { 1 0 1 ¯ 2 } twinning is also discussed.
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Precipitate characteristics and their effect on the Prismatic-Slip-dominated deformation behaviour of an Mg–6 Zn alloy
Acta Materialia, 2013Co-Authors: Jayant Jain, Pavel Cizek, Warren J. Poole, Matthew BarnettAbstract:Abstract This study provides a detailed quantitative characterization of precipitation in an Mg–6 Zn alloy. Transmission electron microscopy (TEM) was used to characterize the average size, aspect ratio and volume fraction of the rod-shaped precipitates for ageing at 200 °C. The effect of these precipitate characteristics on the Prismatic-Slip-dominated deformation behaviour of the above alloy has been evaluated. In particular, their effect on the yield strength and work hardening behaviour of the alloy has been determined. The potential role of Zn solute in solution on the rate of dynamic recovery is discussed. TEM was also used to examine the precipitate–dislocation interaction mechanism on the prism plane in various precipitation states. It was found that the Orowan equation is appropriate for predicting the strengthening on the prism and basal planes due to rod-shaped precipitates.
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effect of zn concentration and grain size on Prismatic Slip in mg zn binary alloys
Magnesium Technology, 2012Co-Authors: Nicole Stanford, Matthew BarnettAbstract:Mg-Zn binary alloys with concentrations between 0 and 2.8wt% Zn have been prepared and processed via hot rolling and annealing to produce specimens with a strong basal texture and a range of grain sizes. These have been deformed in tension, a condition in which the deformation is dominated by Prismatic Slip. This data has been used to assess the Hall-Petch parameter as a function of Zn concentration for deformation dominated by Prismatic Slip. Pure magnesium showed non-linear Hall-Petch behaviour at large grain sizes, and this is compared to the values for Prismatic Slip measured on single crystals. The differences between critical resolved shear stress measurements made through single crystal, polycrystal and mathematical modelling techniques are also discussed.
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Magnesium Technology 2012 - Effect of Zn concentration and grain size on Prismatic Slip in Mg-Zn binary alloys
Magnesium Technology 2012, 2012Co-Authors: Nicole Stanford, Matthew BarnettAbstract:Mg-Zn binary alloys with concentrations between 0 and 2.8wt% Zn have been prepared and processed via hot rolling and annealing to produce specimens with a strong basal texture and a range of grain sizes. These have been deformed in tension, a condition in which the deformation is dominated by Prismatic Slip. This data has been used to assess the Hall-Petch parameter as a function of Zn concentration for deformation dominated by Prismatic Slip. Pure magnesium showed non-linear Hall-Petch behaviour at large grain sizes, and this is compared to the values for Prismatic Slip measured on single crystals. The differences between critical resolved shear stress measurements made through single crystal, polycrystal and mathematical modelling techniques are also discussed.
Kazuki Takashima - One of the best experts on this subject based on the ideXlab platform.
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Temperature dependence of Prismatic Slip in a single-crystalline long-period stacking ordered Mg–Zn–Y alloy
Scripta Materialia, 2020Co-Authors: Kosuke Takagi, Michiaki Yamasaki, Yoji Mine, Kazuki TakashimaAbstract:Abstract Micro-double-shear tests were performed in the temperature range of 298–673 K to quantify the temperature dependence of Prismatic Slip in a long-period stacking ordered Mg85Zn6Y9. The room-temperature critical resolved shear stress (CRSS) for the Prismatic Slip was measured ~261 MPa, which was an order of magnitude higher than ~28 MPa for the basal Slip. Although the basal Slip exhibited less temperature dependence of CRSS, the CRSS for the Prismatic Slip had a gradual transition over 523 K, decreasing to ~110 MPa at 673 K. The Prismatic Slips were promoted through cross-Slip onto the basal plane over the transition temperature.
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Fatigue crack growth behaviour in single-colony lamellar structure of Ti–6Al–4V
Scripta Materialia, 2019Co-Authors: Yoji Mine, Shunsuke Katashima, Rengen Ding, Paul Bowen, Kazuki TakashimaAbstract:Abstract Microstructural fatigue crack growth in Ti–6Al–4V lamellar colonies was examined using small compact-tension specimens, with post-fatigue-test transmission electron microscopy for a mechanistic understanding of the anisotropy. In colonies oriented favourably for Prismatic Slip in the α phase, the crack grew by alternating shearing on two symmetrically arranged Prismatic Slip planes (unzipping process). Interlamellar decohesion along the α/β interface significantly increased the crack growth rate, which depended on the lamellar orientation. When the colony was loaded along [0001], deflected crack growth was accompanied by basal Slip and pyramidal Slip gliding, and the crack growth rates slightly exceeded those during unzipping.
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plasticity and crack extension in single crystalline long period stacking ordered structures of mg85zn6y9 alloy under micro bending
Journal of Alloys and Compounds, 2017Co-Authors: Yoji Mine, Ryo Maezono, Tsuyoshi Mayama, Jing Wu, Y L Chiu, P Bowen, Kazuki TakashimaAbstract:Abstract Micro-bending tests were performed on single-crystalline cantilever beams of long-period stacking ordered (LPSO) structures of Mg 85 Zn 6 Y 9 alloy with and without a notch to study crystal plasticity and cracking behaviour under basal and non-basal Slip conditions. The activation of basal Slip induced load drops during the deformation of a plain cantilever beam with the bending moment perpendicular to the basal plane. A cantilever sample oriented for Prismatic Slip exhibited high yield stress and moderate strain hardening. The apparent critical resolved shear stress (CRSS) for Prismatic Slip was determined to be ∼360 MPa, significantly higher than 30 MPa CRSS determined for basal Slip. A crystal plasticity finite element analysis of the micro-bending test on the sample oriented for Prismatic Slip was performed to verify the CRSS values determined. In addition, the intrinsic fracture resistance for crack growth along the a > direction on a Prismatic plane is higher than that for crack growth along the a > direction on a basal plane. In combination, these results indicate that inhibition of basal Slip activity contributes not only to high strength but also to high intrinsic toughness observed in this LPSO structure.