The Experts below are selected from a list of 123 Experts worldwide ranked by ideXlab platform
Liang Zuo - One of the best experts on this subject based on the ideXlab platform.
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Crossing twin of Ni–Mn–Ga 7M martensite induced by thermo-mechanical treatment
Acta Materialia, 2020Co-Authors: Jiaxing Chen, Bo Yang, Naifu Zou, Y. D. Zhang, Claude Esling, Xiang Zhao, Liang ZuoAbstract:Thermo-mechanical treatment is an effective way to tune the microstructure and enhance the output strain of NiMn-based magnetic shape memory alloys through field driven variant reorientation or structural transformation. Comprehensive knowledge on the microstructural feature and related transformation crystallography is of great importance for the microstructure control and property optimization. In this work, we demonstrate the crossing twin of seven-layered modulated (7 M) martensite assembled in herringbone shape induced by thermo-mechanical treatment in a directionally solidified Ni50Mn30Ga20 alloy. Based on the electron backscatter diffraction (EBSD) measurements, it is found that the crossing twin is composed of four 7 M martensite variants with two mutually crossing systems of twin, i.e., type I twin and compound twin. The type I twin in the crossing twin, being with {1 –2 10}7 M as the Twinning Plane, is quite different from that of the self-accommodated martensite (i.e., {1 –2 –10}7 M as the Twinning Plane). A novel transformation orientation relationship between austenite and 7 M martensite in crossing twin is resolved to be {1 0 1}A//{1 –2 10}7 M and A//7 M, in contrast to that of self-accommodated case, i.e., {1 0 1}A//{1 –2 –10}7 M and A//7 M. By using the experimentally determined orientation relationship between two phases to construct the deformation gradient matrix, the underlying mechanism for the selection of Twinning system is further discussed.
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Microstructural and Crystallographic Insights in a Martensite/Austenite Dual Phase Ni-Mn-Sb Alloy
Advanced Engineering Materials, 2018Co-Authors: Chunyang Zhang, Y. D. Zhang, Claude Esling, Xiang Zhao, Haile Yan, Liang ZuoAbstract:For Ni–Mn–Sb multifunctional alloy, its microstructure and crystallographic information are decisive factors for its multiple magnetic field induced properties, such as magnetic field induced shape memory effect, magneto‐caloric effect, exchange bias effect, and so on. While, studies on such field are rarely conducted. In the present work, a thorough study on microstructural features and crystallographic characteristics has been conducted in a martensite/austenite dual phase coexisting polycrystalline Ni50Mn37Sb13 alloy. Results show that the martensite is self‐organized in plates in the original austenite. The intra‐plate martensite presents a fine lamellar microstructure and each fine lamella corresponds to one martensite variant. Crystallographic orientation analysis indicates that each martensite plate exists four differently oriented martensite variants and they can form three types of twins, type I, type II, and compound twin. Trace analysis results show that the interface between adjacent variants are their Twinning Plane K1. Further investigation on martensitic transformation orientation relationship reveals that the Pitsch orientation relationship, specified as urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0051//urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0052and urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0053//urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0054, is the effective one from austenite to martensite. All the above results offer basic microstructural and crystallographic information on Ni–Mn–Sb alloys and can be useful for further investigation on property optimization of these alloys.
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Crystallographic features of the martensitic transformation and their impact on variant organization in the intermetallic compound Ni 50 Mn 38 Sb 12 studied by SEM/EBSD
International Union of Crystallography journal, 2017Co-Authors: Chunyang Zhang, Y. D. Zhang, Claude Esling, Xiang Zhao, Liang ZuoAbstract:The mechanical and magnetic properties of Ni–Mn–Sb intermetallic compounds are closely related to the martensitic transformation and martensite variant organization. However, studies of these issues are very limited. Thus, a thorough crystallographic investigation of the martensitic transformation orientation relationship (OR), the transformation deformation and their impact on the variant organization of an Ni50Mn38Sb12 alloy using scanning electron microscopy/electron backscatter diffraction (SEM/EBSD) was conducted in this work. It is shown that the martensite variants are hierarchically organized into plates, each possessing four distinct twin-related variants, and the plates into plate colonies, each containing four distinct plates delimited by compatible and incompatible plate interfaces. Such a characteristic organization is produced by the martensitic transformation. It is revealed that the transformation obeys the Pitsch relation ({0[{\overline 1}{\overline 1}]}A // {2[{\overline 2}{\overline 1}]}M and 〈0[{\overline 1}]1〉A // 〈[{\overline 1}{\overline 2}]2〉M; the subscripts A and M refer to austenite and martensite, respectively). The type I Twinning Plane K1 of the intra-plate variants and the compatible plate interface Plane correspond to the respective orientation relationship Planes {0[{\overline 1}{\overline 1}]}A and {0[{\overline 1}{\overline 1}]}A of austenite. The three {0[{\overline 1}{\overline 1}]}A Planes possessed by each pair of compatible plates, one corresponding to the compatible plate interface and the other two to the variants in the two plates, are interrelated by 60° and belong to a single 〈11[{\overline 1}]〉A axis zone. The {0[{\overline 1}{\overline 1}]}A Planes representing the two pairs of compatible plates in each plate colony belong to two 〈11[{\overline 1}]〉A axis zones having one {0[{\overline 1}{\overline 1}]}A Plane in common. This common Plane defines the compatible plate interfaces of the two pairs of plates. The transformation strains to form the variants in the compatible plates are compatible and demonstrate an edge-to-edge character. Thus, such plates should nucleate and grow simultaneously. On the other hand, the strains to form the variants in the incompatible plates are incompatible, so they nucleate and grow separately until they meet during the transformation. The results of the present work provide comprehensive information on the martensitic transformation of Ni–Mn–Sb intermetallic compounds and its impact on martensite variant organization.
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Crystallographic insights into Ni–Co–Mn–In metamagnetic shape memory alloys
Journal of Applied Crystallography, 2016Co-Authors: Haile Yan, Y. D. Zhang, Claude Esling, Xiang Zhao, Chunyang Zhang, Xinli Wang, Liang ZuoAbstract:In the present work, the morphological and crystallographic features of the 6M modulated martensite in the Ni45Co5Mn37In13 alloy were investigated by electron backscatter diffraction and high-resolution transmission electron microscopy (HRTEM) at room temperature. The 6M modulated martensite is in plate form and organized in colonies within which the plates stretch roughly in the same direction. Each colony has four types of orientation variants that are related to three kinds of twin relations, i.e. \{ 1 \bar 2\bar 3\} _{\rm M} type I, \langle \bar 3\bar 3{{1}} \rangle _{\rm M} type II and {{\{ 103\} }}_{\rm M} compound twins. The Twinning shears of type I and type II twins are the same and equal to 0.2681, being about one order of magnitude higher than that of the compound twin (0.0330). Variant interfaces are microscopically defined by their corresponding Twinning Plane K1. The HRTEM investigations show that the interfaces of the type I twin are straight and coherent at atomic scale, whereas those of the type II and compound twins are `stepped'. The step height of the compound twin interfaces is much larger than that of the type II twin interfaces. In view of variant organization, there is only one oriented type I interface and one compound twin interface, but there are two oriented type II interfaces which have an angular deviation of ±5.32° with respect to the type I twin interface. The results of the present work provide comprehensive information on morphological and crystallographic features of Ni–Co–Mn–In metamagnetic shape memory alloys.
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Crystal structure of modulated martensite and crystallographic correlations between martensite variants of Ni 50 Mn 38 Sn 12 alloy
Journal of Applied Crystallography, 2016Co-Authors: Chunqing Lin, Y. D. Zhang, Claude Esling, Xiang Zhao, Haile Yan, Liang ZuoAbstract:A comprehensive study on the crystal structure, the microstructure and the crystallographic features of the martensite in an Ni50Mn38Sn12 alloy has been conducted in the present work. The results show that the martensite possesses a 4O modulated structure. The martensite is organized into broad plates in the original austenite grain. The plates contain irregularly shaped colonies with two characteristic microstructural patterns: a classical lamellar pattern and a herringbone pattern. Crystallographic analyses by scanning electron microscopy/electron backscatter diffraction demonstrate that in each colony there are four orientation variants (A, B, C and D) and they form three types of twins (type I, type II and compound twin). The interfaces between corresponding variants are coincident with their Twinning Plane K1. The interface Planes of the compound twin pairs A&D and B&C can have one or two different orientations, which leads to the two microstructural patterns. The corresponding variants in neighboring colonies within one broad plate (intra-plate colonies) possess close orientations, but the type I and the type II twin relationships are interchanged. The variants in neighboring colonies situated in adjacent plates (inter-plate colonies) are type I or type II twin related but with some angular deviations. The plate interface is defined by the {221} Plane of the variant pair with largest thickness. The results of the present work provide comprehensive microstructural and crystallographic information on modulated martensite in NiMnSn alloys that is useful for the understanding of their specific functionalities and helpful for further investigation on property optimization of these materials.
Joseph Indekeu - One of the best experts on this subject based on the ideXlab platform.
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Interfacial phase transitions in Twinning-Plane superconductors
Physical Review B, 2002Co-Authors: F Clarysse, Joseph IndekeuAbstract:Within the framework of Ginzburg-Landau theory we study the rich variety of interfacial phase transitions in Twinning-Plane superconductors. We show that the phase behavior strongly depends on the transparency of the Twinning Plane for electrons measured by means of the coupling parameter ${\ensuremath{\alpha}}_{\mathrm{TP}}.$ By analyzing the solutions of the Ginzburg-Landau equations in the limit of perfectly transparent Twinning Planes, we predict a first-order interface delocalization transition for all type-I materials. We further perform a detailed study of the other limit in which the Twinning Plane is opaque. The phase diagram proves to be very rich and fundamentally different from the transparent case, recovering many of the results for a system with an external surface. In particular both first-order and critical delocalization transitions are found to be possible, accompanied by a first-order depinning transition. We provide a comparison with experimental results and discuss the relevance of our findings for type-II materials.
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Depinning transition of the superconducting/normal interface in low-κ Twinning-Plane superconductors: interface potential and interface displacement
Physica C-superconductivity and Its Applications, 1997Co-Authors: G Backx, Joseph IndekeuAbstract:Abstract We study the phase transition in which a superconductor/normal interface depins from a Twinning Plane in a type-I superconductor. This transition is a variant of the recently discovered interface delocalization or “wetting” transition in similar materials. We calculate the phase diagram of the depinning transition as a function of the Twinning-Plane transparency for electron, and the local enhancement of superconductivity. We focus on the limit of strongly type-I materials, κ → 0, in which analytic results can be obtained. We further compute the interface potential V ( l ) and use that to calculate the displacement profile l ( y ) of the transition zone between a pinned and a depinned superconducting/normal interface in the vicinity of a Twinning Plane. In principle, the interface displacement profile can be probed experimentally by measuring the location of the jump in the magnetic induction between the superconducting and normal phases.
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depinning transition of the superconducting normal interface in low κ Twinning Plane superconductors interface potential and interface displacement
Physica C-superconductivity and Its Applications, 1997Co-Authors: G Backx, Joseph IndekeuAbstract:Abstract We study the phase transition in which a superconductor/normal interface depins from a Twinning Plane in a type-I superconductor. This transition is a variant of the recently discovered interface delocalization or “wetting” transition in similar materials. We calculate the phase diagram of the depinning transition as a function of the Twinning-Plane transparency for electron, and the local enhancement of superconductivity. We focus on the limit of strongly type-I materials, κ → 0, in which analytic results can be obtained. We further compute the interface potential V ( l ) and use that to calculate the displacement profile l ( y ) of the transition zone between a pinned and a depinned superconducting/normal interface in the vicinity of a Twinning Plane. In principle, the interface displacement profile can be probed experimentally by measuring the location of the jump in the magnetic induction between the superconducting and normal phases.
Claude Esling - One of the best experts on this subject based on the ideXlab platform.
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Crossing twin of Ni–Mn–Ga 7M martensite induced by thermo-mechanical treatment
Acta Materialia, 2020Co-Authors: Jiaxing Chen, Bo Yang, Naifu Zou, Y. D. Zhang, Claude Esling, Xiang Zhao, Liang ZuoAbstract:Thermo-mechanical treatment is an effective way to tune the microstructure and enhance the output strain of NiMn-based magnetic shape memory alloys through field driven variant reorientation or structural transformation. Comprehensive knowledge on the microstructural feature and related transformation crystallography is of great importance for the microstructure control and property optimization. In this work, we demonstrate the crossing twin of seven-layered modulated (7 M) martensite assembled in herringbone shape induced by thermo-mechanical treatment in a directionally solidified Ni50Mn30Ga20 alloy. Based on the electron backscatter diffraction (EBSD) measurements, it is found that the crossing twin is composed of four 7 M martensite variants with two mutually crossing systems of twin, i.e., type I twin and compound twin. The type I twin in the crossing twin, being with {1 –2 10}7 M as the Twinning Plane, is quite different from that of the self-accommodated martensite (i.e., {1 –2 –10}7 M as the Twinning Plane). A novel transformation orientation relationship between austenite and 7 M martensite in crossing twin is resolved to be {1 0 1}A//{1 –2 10}7 M and A//7 M, in contrast to that of self-accommodated case, i.e., {1 0 1}A//{1 –2 –10}7 M and A//7 M. By using the experimentally determined orientation relationship between two phases to construct the deformation gradient matrix, the underlying mechanism for the selection of Twinning system is further discussed.
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Microstructural and Crystallographic Insights in a Martensite/Austenite Dual Phase Ni-Mn-Sb Alloy
Advanced Engineering Materials, 2018Co-Authors: Chunyang Zhang, Y. D. Zhang, Claude Esling, Xiang Zhao, Haile Yan, Liang ZuoAbstract:For Ni–Mn–Sb multifunctional alloy, its microstructure and crystallographic information are decisive factors for its multiple magnetic field induced properties, such as magnetic field induced shape memory effect, magneto‐caloric effect, exchange bias effect, and so on. While, studies on such field are rarely conducted. In the present work, a thorough study on microstructural features and crystallographic characteristics has been conducted in a martensite/austenite dual phase coexisting polycrystalline Ni50Mn37Sb13 alloy. Results show that the martensite is self‐organized in plates in the original austenite. The intra‐plate martensite presents a fine lamellar microstructure and each fine lamella corresponds to one martensite variant. Crystallographic orientation analysis indicates that each martensite plate exists four differently oriented martensite variants and they can form three types of twins, type I, type II, and compound twin. Trace analysis results show that the interface between adjacent variants are their Twinning Plane K1. Further investigation on martensitic transformation orientation relationship reveals that the Pitsch orientation relationship, specified as urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0051//urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0052and urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0053//urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0054, is the effective one from austenite to martensite. All the above results offer basic microstructural and crystallographic information on Ni–Mn–Sb alloys and can be useful for further investigation on property optimization of these alloys.
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Crystallographic features of the martensitic transformation and their impact on variant organization in the intermetallic compound Ni 50 Mn 38 Sb 12 studied by SEM/EBSD
International Union of Crystallography journal, 2017Co-Authors: Chunyang Zhang, Y. D. Zhang, Claude Esling, Xiang Zhao, Liang ZuoAbstract:The mechanical and magnetic properties of Ni–Mn–Sb intermetallic compounds are closely related to the martensitic transformation and martensite variant organization. However, studies of these issues are very limited. Thus, a thorough crystallographic investigation of the martensitic transformation orientation relationship (OR), the transformation deformation and their impact on the variant organization of an Ni50Mn38Sb12 alloy using scanning electron microscopy/electron backscatter diffraction (SEM/EBSD) was conducted in this work. It is shown that the martensite variants are hierarchically organized into plates, each possessing four distinct twin-related variants, and the plates into plate colonies, each containing four distinct plates delimited by compatible and incompatible plate interfaces. Such a characteristic organization is produced by the martensitic transformation. It is revealed that the transformation obeys the Pitsch relation ({0[{\overline 1}{\overline 1}]}A // {2[{\overline 2}{\overline 1}]}M and 〈0[{\overline 1}]1〉A // 〈[{\overline 1}{\overline 2}]2〉M; the subscripts A and M refer to austenite and martensite, respectively). The type I Twinning Plane K1 of the intra-plate variants and the compatible plate interface Plane correspond to the respective orientation relationship Planes {0[{\overline 1}{\overline 1}]}A and {0[{\overline 1}{\overline 1}]}A of austenite. The three {0[{\overline 1}{\overline 1}]}A Planes possessed by each pair of compatible plates, one corresponding to the compatible plate interface and the other two to the variants in the two plates, are interrelated by 60° and belong to a single 〈11[{\overline 1}]〉A axis zone. The {0[{\overline 1}{\overline 1}]}A Planes representing the two pairs of compatible plates in each plate colony belong to two 〈11[{\overline 1}]〉A axis zones having one {0[{\overline 1}{\overline 1}]}A Plane in common. This common Plane defines the compatible plate interfaces of the two pairs of plates. The transformation strains to form the variants in the compatible plates are compatible and demonstrate an edge-to-edge character. Thus, such plates should nucleate and grow simultaneously. On the other hand, the strains to form the variants in the incompatible plates are incompatible, so they nucleate and grow separately until they meet during the transformation. The results of the present work provide comprehensive information on the martensitic transformation of Ni–Mn–Sb intermetallic compounds and its impact on martensite variant organization.
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Crystallographic insights into Ni–Co–Mn–In metamagnetic shape memory alloys
Journal of Applied Crystallography, 2016Co-Authors: Haile Yan, Y. D. Zhang, Claude Esling, Xiang Zhao, Chunyang Zhang, Xinli Wang, Liang ZuoAbstract:In the present work, the morphological and crystallographic features of the 6M modulated martensite in the Ni45Co5Mn37In13 alloy were investigated by electron backscatter diffraction and high-resolution transmission electron microscopy (HRTEM) at room temperature. The 6M modulated martensite is in plate form and organized in colonies within which the plates stretch roughly in the same direction. Each colony has four types of orientation variants that are related to three kinds of twin relations, i.e. \{ 1 \bar 2\bar 3\} _{\rm M} type I, \langle \bar 3\bar 3{{1}} \rangle _{\rm M} type II and {{\{ 103\} }}_{\rm M} compound twins. The Twinning shears of type I and type II twins are the same and equal to 0.2681, being about one order of magnitude higher than that of the compound twin (0.0330). Variant interfaces are microscopically defined by their corresponding Twinning Plane K1. The HRTEM investigations show that the interfaces of the type I twin are straight and coherent at atomic scale, whereas those of the type II and compound twins are `stepped'. The step height of the compound twin interfaces is much larger than that of the type II twin interfaces. In view of variant organization, there is only one oriented type I interface and one compound twin interface, but there are two oriented type II interfaces which have an angular deviation of ±5.32° with respect to the type I twin interface. The results of the present work provide comprehensive information on morphological and crystallographic features of Ni–Co–Mn–In metamagnetic shape memory alloys.
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Crystal structure of modulated martensite and crystallographic correlations between martensite variants of Ni 50 Mn 38 Sn 12 alloy
Journal of Applied Crystallography, 2016Co-Authors: Chunqing Lin, Y. D. Zhang, Claude Esling, Xiang Zhao, Haile Yan, Liang ZuoAbstract:A comprehensive study on the crystal structure, the microstructure and the crystallographic features of the martensite in an Ni50Mn38Sn12 alloy has been conducted in the present work. The results show that the martensite possesses a 4O modulated structure. The martensite is organized into broad plates in the original austenite grain. The plates contain irregularly shaped colonies with two characteristic microstructural patterns: a classical lamellar pattern and a herringbone pattern. Crystallographic analyses by scanning electron microscopy/electron backscatter diffraction demonstrate that in each colony there are four orientation variants (A, B, C and D) and they form three types of twins (type I, type II and compound twin). The interfaces between corresponding variants are coincident with their Twinning Plane K1. The interface Planes of the compound twin pairs A&D and B&C can have one or two different orientations, which leads to the two microstructural patterns. The corresponding variants in neighboring colonies within one broad plate (intra-plate colonies) possess close orientations, but the type I and the type II twin relationships are interchanged. The variants in neighboring colonies situated in adjacent plates (inter-plate colonies) are type I or type II twin related but with some angular deviations. The plate interface is defined by the {221} Plane of the variant pair with largest thickness. The results of the present work provide comprehensive microstructural and crystallographic information on modulated martensite in NiMnSn alloys that is useful for the understanding of their specific functionalities and helpful for further investigation on property optimization of these materials.
Xiang Zhao - One of the best experts on this subject based on the ideXlab platform.
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Crossing twin of Ni–Mn–Ga 7M martensite induced by thermo-mechanical treatment
Acta Materialia, 2020Co-Authors: Jiaxing Chen, Bo Yang, Naifu Zou, Y. D. Zhang, Claude Esling, Xiang Zhao, Liang ZuoAbstract:Thermo-mechanical treatment is an effective way to tune the microstructure and enhance the output strain of NiMn-based magnetic shape memory alloys through field driven variant reorientation or structural transformation. Comprehensive knowledge on the microstructural feature and related transformation crystallography is of great importance for the microstructure control and property optimization. In this work, we demonstrate the crossing twin of seven-layered modulated (7 M) martensite assembled in herringbone shape induced by thermo-mechanical treatment in a directionally solidified Ni50Mn30Ga20 alloy. Based on the electron backscatter diffraction (EBSD) measurements, it is found that the crossing twin is composed of four 7 M martensite variants with two mutually crossing systems of twin, i.e., type I twin and compound twin. The type I twin in the crossing twin, being with {1 –2 10}7 M as the Twinning Plane, is quite different from that of the self-accommodated martensite (i.e., {1 –2 –10}7 M as the Twinning Plane). A novel transformation orientation relationship between austenite and 7 M martensite in crossing twin is resolved to be {1 0 1}A//{1 –2 10}7 M and A//7 M, in contrast to that of self-accommodated case, i.e., {1 0 1}A//{1 –2 –10}7 M and A//7 M. By using the experimentally determined orientation relationship between two phases to construct the deformation gradient matrix, the underlying mechanism for the selection of Twinning system is further discussed.
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Microstructural and Crystallographic Insights in a Martensite/Austenite Dual Phase Ni-Mn-Sb Alloy
Advanced Engineering Materials, 2018Co-Authors: Chunyang Zhang, Y. D. Zhang, Claude Esling, Xiang Zhao, Haile Yan, Liang ZuoAbstract:For Ni–Mn–Sb multifunctional alloy, its microstructure and crystallographic information are decisive factors for its multiple magnetic field induced properties, such as magnetic field induced shape memory effect, magneto‐caloric effect, exchange bias effect, and so on. While, studies on such field are rarely conducted. In the present work, a thorough study on microstructural features and crystallographic characteristics has been conducted in a martensite/austenite dual phase coexisting polycrystalline Ni50Mn37Sb13 alloy. Results show that the martensite is self‐organized in plates in the original austenite. The intra‐plate martensite presents a fine lamellar microstructure and each fine lamella corresponds to one martensite variant. Crystallographic orientation analysis indicates that each martensite plate exists four differently oriented martensite variants and they can form three types of twins, type I, type II, and compound twin. Trace analysis results show that the interface between adjacent variants are their Twinning Plane K1. Further investigation on martensitic transformation orientation relationship reveals that the Pitsch orientation relationship, specified as urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0051//urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0052and urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0053//urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0054, is the effective one from austenite to martensite. All the above results offer basic microstructural and crystallographic information on Ni–Mn–Sb alloys and can be useful for further investigation on property optimization of these alloys.
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Crystallographic features of the martensitic transformation and their impact on variant organization in the intermetallic compound Ni 50 Mn 38 Sb 12 studied by SEM/EBSD
International Union of Crystallography journal, 2017Co-Authors: Chunyang Zhang, Y. D. Zhang, Claude Esling, Xiang Zhao, Liang ZuoAbstract:The mechanical and magnetic properties of Ni–Mn–Sb intermetallic compounds are closely related to the martensitic transformation and martensite variant organization. However, studies of these issues are very limited. Thus, a thorough crystallographic investigation of the martensitic transformation orientation relationship (OR), the transformation deformation and their impact on the variant organization of an Ni50Mn38Sb12 alloy using scanning electron microscopy/electron backscatter diffraction (SEM/EBSD) was conducted in this work. It is shown that the martensite variants are hierarchically organized into plates, each possessing four distinct twin-related variants, and the plates into plate colonies, each containing four distinct plates delimited by compatible and incompatible plate interfaces. Such a characteristic organization is produced by the martensitic transformation. It is revealed that the transformation obeys the Pitsch relation ({0[{\overline 1}{\overline 1}]}A // {2[{\overline 2}{\overline 1}]}M and 〈0[{\overline 1}]1〉A // 〈[{\overline 1}{\overline 2}]2〉M; the subscripts A and M refer to austenite and martensite, respectively). The type I Twinning Plane K1 of the intra-plate variants and the compatible plate interface Plane correspond to the respective orientation relationship Planes {0[{\overline 1}{\overline 1}]}A and {0[{\overline 1}{\overline 1}]}A of austenite. The three {0[{\overline 1}{\overline 1}]}A Planes possessed by each pair of compatible plates, one corresponding to the compatible plate interface and the other two to the variants in the two plates, are interrelated by 60° and belong to a single 〈11[{\overline 1}]〉A axis zone. The {0[{\overline 1}{\overline 1}]}A Planes representing the two pairs of compatible plates in each plate colony belong to two 〈11[{\overline 1}]〉A axis zones having one {0[{\overline 1}{\overline 1}]}A Plane in common. This common Plane defines the compatible plate interfaces of the two pairs of plates. The transformation strains to form the variants in the compatible plates are compatible and demonstrate an edge-to-edge character. Thus, such plates should nucleate and grow simultaneously. On the other hand, the strains to form the variants in the incompatible plates are incompatible, so they nucleate and grow separately until they meet during the transformation. The results of the present work provide comprehensive information on the martensitic transformation of Ni–Mn–Sb intermetallic compounds and its impact on martensite variant organization.
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Crystallographic insights into Ni–Co–Mn–In metamagnetic shape memory alloys
Journal of Applied Crystallography, 2016Co-Authors: Haile Yan, Y. D. Zhang, Claude Esling, Xiang Zhao, Chunyang Zhang, Xinli Wang, Liang ZuoAbstract:In the present work, the morphological and crystallographic features of the 6M modulated martensite in the Ni45Co5Mn37In13 alloy were investigated by electron backscatter diffraction and high-resolution transmission electron microscopy (HRTEM) at room temperature. The 6M modulated martensite is in plate form and organized in colonies within which the plates stretch roughly in the same direction. Each colony has four types of orientation variants that are related to three kinds of twin relations, i.e. \{ 1 \bar 2\bar 3\} _{\rm M} type I, \langle \bar 3\bar 3{{1}} \rangle _{\rm M} type II and {{\{ 103\} }}_{\rm M} compound twins. The Twinning shears of type I and type II twins are the same and equal to 0.2681, being about one order of magnitude higher than that of the compound twin (0.0330). Variant interfaces are microscopically defined by their corresponding Twinning Plane K1. The HRTEM investigations show that the interfaces of the type I twin are straight and coherent at atomic scale, whereas those of the type II and compound twins are `stepped'. The step height of the compound twin interfaces is much larger than that of the type II twin interfaces. In view of variant organization, there is only one oriented type I interface and one compound twin interface, but there are two oriented type II interfaces which have an angular deviation of ±5.32° with respect to the type I twin interface. The results of the present work provide comprehensive information on morphological and crystallographic features of Ni–Co–Mn–In metamagnetic shape memory alloys.
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Crystal structure of modulated martensite and crystallographic correlations between martensite variants of Ni 50 Mn 38 Sn 12 alloy
Journal of Applied Crystallography, 2016Co-Authors: Chunqing Lin, Y. D. Zhang, Claude Esling, Xiang Zhao, Haile Yan, Liang ZuoAbstract:A comprehensive study on the crystal structure, the microstructure and the crystallographic features of the martensite in an Ni50Mn38Sn12 alloy has been conducted in the present work. The results show that the martensite possesses a 4O modulated structure. The martensite is organized into broad plates in the original austenite grain. The plates contain irregularly shaped colonies with two characteristic microstructural patterns: a classical lamellar pattern and a herringbone pattern. Crystallographic analyses by scanning electron microscopy/electron backscatter diffraction demonstrate that in each colony there are four orientation variants (A, B, C and D) and they form three types of twins (type I, type II and compound twin). The interfaces between corresponding variants are coincident with their Twinning Plane K1. The interface Planes of the compound twin pairs A&D and B&C can have one or two different orientations, which leads to the two microstructural patterns. The corresponding variants in neighboring colonies within one broad plate (intra-plate colonies) possess close orientations, but the type I and the type II twin relationships are interchanged. The variants in neighboring colonies situated in adjacent plates (inter-plate colonies) are type I or type II twin related but with some angular deviations. The plate interface is defined by the {221} Plane of the variant pair with largest thickness. The results of the present work provide comprehensive microstructural and crystallographic information on modulated martensite in NiMnSn alloys that is useful for the understanding of their specific functionalities and helpful for further investigation on property optimization of these materials.
Y. D. Zhang - One of the best experts on this subject based on the ideXlab platform.
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Crossing twin of Ni–Mn–Ga 7M martensite induced by thermo-mechanical treatment
Acta Materialia, 2020Co-Authors: Jiaxing Chen, Bo Yang, Naifu Zou, Y. D. Zhang, Claude Esling, Xiang Zhao, Liang ZuoAbstract:Thermo-mechanical treatment is an effective way to tune the microstructure and enhance the output strain of NiMn-based magnetic shape memory alloys through field driven variant reorientation or structural transformation. Comprehensive knowledge on the microstructural feature and related transformation crystallography is of great importance for the microstructure control and property optimization. In this work, we demonstrate the crossing twin of seven-layered modulated (7 M) martensite assembled in herringbone shape induced by thermo-mechanical treatment in a directionally solidified Ni50Mn30Ga20 alloy. Based on the electron backscatter diffraction (EBSD) measurements, it is found that the crossing twin is composed of four 7 M martensite variants with two mutually crossing systems of twin, i.e., type I twin and compound twin. The type I twin in the crossing twin, being with {1 –2 10}7 M as the Twinning Plane, is quite different from that of the self-accommodated martensite (i.e., {1 –2 –10}7 M as the Twinning Plane). A novel transformation orientation relationship between austenite and 7 M martensite in crossing twin is resolved to be {1 0 1}A//{1 –2 10}7 M and A//7 M, in contrast to that of self-accommodated case, i.e., {1 0 1}A//{1 –2 –10}7 M and A//7 M. By using the experimentally determined orientation relationship between two phases to construct the deformation gradient matrix, the underlying mechanism for the selection of Twinning system is further discussed.
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Microstructural and Crystallographic Insights in a Martensite/Austenite Dual Phase Ni-Mn-Sb Alloy
Advanced Engineering Materials, 2018Co-Authors: Chunyang Zhang, Y. D. Zhang, Claude Esling, Xiang Zhao, Haile Yan, Liang ZuoAbstract:For Ni–Mn–Sb multifunctional alloy, its microstructure and crystallographic information are decisive factors for its multiple magnetic field induced properties, such as magnetic field induced shape memory effect, magneto‐caloric effect, exchange bias effect, and so on. While, studies on such field are rarely conducted. In the present work, a thorough study on microstructural features and crystallographic characteristics has been conducted in a martensite/austenite dual phase coexisting polycrystalline Ni50Mn37Sb13 alloy. Results show that the martensite is self‐organized in plates in the original austenite. The intra‐plate martensite presents a fine lamellar microstructure and each fine lamella corresponds to one martensite variant. Crystallographic orientation analysis indicates that each martensite plate exists four differently oriented martensite variants and they can form three types of twins, type I, type II, and compound twin. Trace analysis results show that the interface between adjacent variants are their Twinning Plane K1. Further investigation on martensitic transformation orientation relationship reveals that the Pitsch orientation relationship, specified as urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0051//urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0052and urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0053//urn:x-wiley:14381656:media:adem201700221:adem201700221-math-0054, is the effective one from austenite to martensite. All the above results offer basic microstructural and crystallographic information on Ni–Mn–Sb alloys and can be useful for further investigation on property optimization of these alloys.
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Crystallographic features of the martensitic transformation and their impact on variant organization in the intermetallic compound Ni 50 Mn 38 Sb 12 studied by SEM/EBSD
International Union of Crystallography journal, 2017Co-Authors: Chunyang Zhang, Y. D. Zhang, Claude Esling, Xiang Zhao, Liang ZuoAbstract:The mechanical and magnetic properties of Ni–Mn–Sb intermetallic compounds are closely related to the martensitic transformation and martensite variant organization. However, studies of these issues are very limited. Thus, a thorough crystallographic investigation of the martensitic transformation orientation relationship (OR), the transformation deformation and their impact on the variant organization of an Ni50Mn38Sb12 alloy using scanning electron microscopy/electron backscatter diffraction (SEM/EBSD) was conducted in this work. It is shown that the martensite variants are hierarchically organized into plates, each possessing four distinct twin-related variants, and the plates into plate colonies, each containing four distinct plates delimited by compatible and incompatible plate interfaces. Such a characteristic organization is produced by the martensitic transformation. It is revealed that the transformation obeys the Pitsch relation ({0[{\overline 1}{\overline 1}]}A // {2[{\overline 2}{\overline 1}]}M and 〈0[{\overline 1}]1〉A // 〈[{\overline 1}{\overline 2}]2〉M; the subscripts A and M refer to austenite and martensite, respectively). The type I Twinning Plane K1 of the intra-plate variants and the compatible plate interface Plane correspond to the respective orientation relationship Planes {0[{\overline 1}{\overline 1}]}A and {0[{\overline 1}{\overline 1}]}A of austenite. The three {0[{\overline 1}{\overline 1}]}A Planes possessed by each pair of compatible plates, one corresponding to the compatible plate interface and the other two to the variants in the two plates, are interrelated by 60° and belong to a single 〈11[{\overline 1}]〉A axis zone. The {0[{\overline 1}{\overline 1}]}A Planes representing the two pairs of compatible plates in each plate colony belong to two 〈11[{\overline 1}]〉A axis zones having one {0[{\overline 1}{\overline 1}]}A Plane in common. This common Plane defines the compatible plate interfaces of the two pairs of plates. The transformation strains to form the variants in the compatible plates are compatible and demonstrate an edge-to-edge character. Thus, such plates should nucleate and grow simultaneously. On the other hand, the strains to form the variants in the incompatible plates are incompatible, so they nucleate and grow separately until they meet during the transformation. The results of the present work provide comprehensive information on the martensitic transformation of Ni–Mn–Sb intermetallic compounds and its impact on martensite variant organization.
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Crystallographic insights into Ni–Co–Mn–In metamagnetic shape memory alloys
Journal of Applied Crystallography, 2016Co-Authors: Haile Yan, Y. D. Zhang, Claude Esling, Xiang Zhao, Chunyang Zhang, Xinli Wang, Liang ZuoAbstract:In the present work, the morphological and crystallographic features of the 6M modulated martensite in the Ni45Co5Mn37In13 alloy were investigated by electron backscatter diffraction and high-resolution transmission electron microscopy (HRTEM) at room temperature. The 6M modulated martensite is in plate form and organized in colonies within which the plates stretch roughly in the same direction. Each colony has four types of orientation variants that are related to three kinds of twin relations, i.e. \{ 1 \bar 2\bar 3\} _{\rm M} type I, \langle \bar 3\bar 3{{1}} \rangle _{\rm M} type II and {{\{ 103\} }}_{\rm M} compound twins. The Twinning shears of type I and type II twins are the same and equal to 0.2681, being about one order of magnitude higher than that of the compound twin (0.0330). Variant interfaces are microscopically defined by their corresponding Twinning Plane K1. The HRTEM investigations show that the interfaces of the type I twin are straight and coherent at atomic scale, whereas those of the type II and compound twins are `stepped'. The step height of the compound twin interfaces is much larger than that of the type II twin interfaces. In view of variant organization, there is only one oriented type I interface and one compound twin interface, but there are two oriented type II interfaces which have an angular deviation of ±5.32° with respect to the type I twin interface. The results of the present work provide comprehensive information on morphological and crystallographic features of Ni–Co–Mn–In metamagnetic shape memory alloys.
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Crystal structure of modulated martensite and crystallographic correlations between martensite variants of Ni 50 Mn 38 Sn 12 alloy
Journal of Applied Crystallography, 2016Co-Authors: Chunqing Lin, Y. D. Zhang, Claude Esling, Xiang Zhao, Haile Yan, Liang ZuoAbstract:A comprehensive study on the crystal structure, the microstructure and the crystallographic features of the martensite in an Ni50Mn38Sn12 alloy has been conducted in the present work. The results show that the martensite possesses a 4O modulated structure. The martensite is organized into broad plates in the original austenite grain. The plates contain irregularly shaped colonies with two characteristic microstructural patterns: a classical lamellar pattern and a herringbone pattern. Crystallographic analyses by scanning electron microscopy/electron backscatter diffraction demonstrate that in each colony there are four orientation variants (A, B, C and D) and they form three types of twins (type I, type II and compound twin). The interfaces between corresponding variants are coincident with their Twinning Plane K1. The interface Planes of the compound twin pairs A&D and B&C can have one or two different orientations, which leads to the two microstructural patterns. The corresponding variants in neighboring colonies within one broad plate (intra-plate colonies) possess close orientations, but the type I and the type II twin relationships are interchanged. The variants in neighboring colonies situated in adjacent plates (inter-plate colonies) are type I or type II twin related but with some angular deviations. The plate interface is defined by the {221} Plane of the variant pair with largest thickness. The results of the present work provide comprehensive microstructural and crystallographic information on modulated martensite in NiMnSn alloys that is useful for the understanding of their specific functionalities and helpful for further investigation on property optimization of these materials.
