NIMS Award Symposium 2023｜Abstracts
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Activation of Non Type Dislocations and Damping Capacity Improvement by Activation of Non Type Dislocations and Damping Capacity Improvement by Deformation Induced MDeformation Induced M E. Chandiran 1, Y. Ogawa 1, R. Ueji 1, A. Singh 1, H. Somekawa1 and T. Ohmura1 1 Research Center for Structural Materials, National Institute for Materials Science (NIMS) E. Chandiran 1, Y. Ogawa 1, R. Ueji 1, A. Singh 1, H. Somekawa1 and T. Ohmura1 1 Research Center for Structural Materials, National Institute for Materials Science (NIMS) Excellent strength-to-weight ratio of magnesium (Mg) alloys makes them desirable for structural Excellent strength-to-weight ratio of magnesium (Mg) alloys makes them desirable for structural applications. However, the room-temperature formability of wrought Mg alloys should be improved for applications. However, the room-temperature formability of wrought Mg alloys should be improved for wider applicability. Addition of rare earth elements such as Sc results in a better combination of strength wider applicability. Addition of rare earth elements such as Sc results in a better combination of strength and ductility, likely due to enhancement of non-basal dislocation slip. Nonetheless, it is unclear how Sc and ductility, likely due to enhancement of non-basal dislocation slip. Nonetheless, it is unclear how Sc addition affects the deformation mechanisms of Mg, particularly in the early stages of deformation. As addition affects the deformation mechanisms of Mg, particularly in the early stages of deformation. As a result, effect of Sc addition on deformation behavior of a near-<0001> oriented Mg-alloy grain during a result, effect of Sc addition on deformation behavior of a near-<0001> oriented Mg-alloy grain during micropillar compression has been investigated in this study. It was found that the addition of Sc micropillar compression has been investigated in this study. It was found that the addition of Sc increases yield stress and also promoted formation of type dislocation slip while the formation increases yield stress and also promoted formation of type dislocation slip while the formation of type dislocation slip is inhibited. This demonstrates that alloying Mg with Sc enhances ductility of type dislocation slip is inhibited. This demonstrates that alloying Mg with Sc enhances ductility by increasing activation of non- type dislocations. by increasing activation of non- type dislocations. In addition to the above study, the effect of grain orientation on damping capacity (tanδ) is investigated In addition to the above study, the effect of grain orientation on damping capacity (tanδ) is investigated in a Mg-Sc alloy with a hexagonal close-packed structure (HCP Mg-Sc) and a body-centered cubic in a Mg-Sc alloy with a hexagonal close-packed structure (HCP Mg-Sc) and a body-centered cubic structure (BCC Mg-Sc), using nano-dynamic mechanical analysis. The damping capacity of HCP Mg-structure (BCC Mg-Sc), using nano-dynamic mechanical analysis. The damping capacity of HCP Mg-Sc was found to be less dependent on grain orientation, whereas it was significantly dependent on grain Sc was found to be less dependent on grain orientation, whereas it was significantly dependent on grain orientation in BCC Mg-Sc. The deformation-induced transformation of BCC to orthorhombic martensite orientation in BCC Mg-Sc. The deformation-induced transformation of BCC to orthorhombic martensite in grain aligned close to <111> contributed to improved damping capacity compared to other two in grain aligned close to <111> contributed to improved damping capacity compared to other two orientations <001> and <101>. orientations <001> and <101>. 3D Visualization of Hydrogen Trapping Sites in Al-Zn-Mg Alloys 3D Visualization of Hydrogen Trapping Sites in Al-Zn-Mg Alloys R. Abe 1, K. Shimizu 1, T.T. Sasaki2, H. Toda3 and Y. Kamada 1 1 Department of Physical Science and Materials Engineering, Iwate University R. Abe 1, K. Shimizu 1, T.T. Sasaki2, H. Toda3 and Y. Kamada 1 2 Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS) 1 Department of Physical Science and Materials Engineering, Iwate University 3 Department of Mechanical Engineering, Kyushu University 2 Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS) 3 Department of Mechanical Engineering, Kyushu University A critical issue with high-strength wrought Al-Zn-Mg alloys is their low resistance to hydrogen A critical issue with high-strength wrought Al-Zn-Mg alloys is their low resistance to hydrogen embrittlement, which hinders the application of Al-Zn-Mg alloys with higher strength classes than embrittlement, which hinders the application of Al-Zn-Mg alloys with higher strength classes than commercial ones. A recent ab-initio study revealed that this could be due to hydrogen trapping at the commercial ones. A recent ab-initio study revealed that this could be due to hydrogen trapping at the precipitate/matrix interfaces, which semi-spontaneous debonding at these interfaces [1]. Imaging of precipitate/matrix interfaces, which semi-spontaneous debonding at these interfaces [1]. Imaging of hydrogen trapping sites would validate this hypothesis or elucidate an alternative mechanism for hydrogen trapping sites would validate this hypothesis or elucidate an alternative mechanism for hydrogen embrittlement in Al-Mg-Zn alloys, thus providing a detailed design strategy with excellent hydrogen embrittlement in Al-Mg-Zn alloys, thus providing a detailed design strategy with excellent resistance to hydrogen embrittlement. In this study, we attempted to visualize the hydrogen trapping site resistance to hydrogen embrittlement. In this study, we attempted to visualize the hydrogen trapping site in an artificially aged Al-Zn-Mg alloy using a threein an artificially aged Al-Zn-Mg alloy using a threeThe sample was charged with deuterium (D) to distinguish from residual hydrogen in the 3DAP The sample was charged with deuterium (D) to distinguish from residual hydrogen in the 3DAP analysis chamber, followed by 3DAP analysis. The obtained 3D atom map showed the enrichment of D analysis chamber, followed by 3DAP analysis. The obtained 3D atom map showed the enrichment of D around the η precipitates within the grain and those along the grain boundaries. Line composition around the η precipitates within the grain and those along the grain boundaries. Line composition profiles across the η precipitates show the depletion of D within the precipitate and the enrichment of D profiles across the η precipitates show the depletion of D within the precipitate and the enrichment of D at a specific η/matrix interface, suggesting that hydrogen trapped at the semi-coherent η/matrix interface at a specific η/matrix interface, suggesting that hydrogen trapped at the semi-coherent η/matrix interface facilitated interface decohesion could lead to the low resistance to hydrogen embrittlement. facilitated interface decohesion could lead to the low resistance to hydrogen embrittlement. [1] T. Tsuru, et al., Scientific Reports, 10:1998, 1-8(2020). [1] T. Tsuru, et al., Scientific Reports, 10:1998, 1-8(2020). 62PP33--0099 PP33--0099 PP33--1100 PP33--1100 artensitic Transformation in artensitic Transformation in Poster Presentation ｜NIMS Award Symposium 2023-dimensional atom probe (3DAP). -dimensional atom probe (3DAP). P3 ｜ EvaluationMg-Sc Alloy Mg-Sc Alloy

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