Crystallographic insights into Ni–Co–Mn–In metamagnetic shape memory alloys

2016 ◽  
Vol 49 (5) ◽  
pp. 1585-1592 ◽  
Author(s):  
Haile Yan ◽  
Chunyang Zhang ◽  
Yudong Zhang ◽  
Xinli Wang ◽  
Claude Esling ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Electron Backscatter Diffraction ◽  
Atomic Scale ◽  
Type I ◽  
Angular Deviation ◽  
Type Ii ◽  
Twin Interface ◽  
Transmission Electron ◽  
Order Of Magnitude

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 K 1. 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.

scholarly journals Crystallographic insights into diamond-shaped 7M martensite in Ni–Mn–Ga ferromagnetic shape-memory alloys

IUCrJ ◽  
2019 ◽  
Vol 6 (5) ◽  
pp. 909-920 ◽  
Author(s):  
Zong-Bin Li ◽  
Bo Yang ◽  
Yu-Dong Zhang ◽  
Claude Esling ◽  
Xiang Zhao ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Electron Backscatter Diffraction ◽  
Deformation Gradient ◽  
Type I ◽  
Magnetic Shape Memory ◽  
Ferromagnetic Shape Memory Alloys ◽  
Ferromagnetic Shape Memory ◽  
Habit Planes

For Heusler-type Ni–Mn–Ga ferromagnetic shape-memory alloys, the configuration of the martensite variants is a decisive factor in achieving a large magnetic shape-memory effect through field-induced variant reorientation. Based upon the spatially resolved electron backscatter diffraction technique, the microstructural evolution associated with the martensitic transformation from austenite to seven-layered modulated (7M) martensite was investigated on a polycrystalline Ni53Mn22Ga25 alloy. It was clearly shown that grain interior nucleation led to the formation of diamond-shaped 7M martensite within the parent austenite matrix. This diamond microstructure underwent further growth through an isotropic expansion with the coordinated outward movement of four side habit planes, followed by an anisotropic elongation with the forward extension of a type-I twin pair. A two-step growth model is proposed to describe the specific morphology and crystallography of 7M martensite. In addition, the habit planes were revealed to possess a stepped structure, with the {1 0 1}A plane as the terrace and the {0 1 0}A plane as the step. The characteristic combination of martensite variants and the underlying mechanism of self-accommodation in the martensitic transformation have been analysed in terms of the minimum total transformation strain, where the deformation gradient matrix was constructed according to the experimentally determined orientation relationship between the two phases. The present results may deepen the understanding of special martensite microstructures during the martensitic transformation in ferromagnetic shape-memory alloys.

Crystal structure of modulated martensite and crystallographic correlations between martensite variants of Ni50Mn38Sn12alloy

2016 ◽  
Vol 49 (4) ◽  
pp. 1276-1283 ◽  
Author(s):  
Chunqing Lin ◽  
Haile Yan ◽  
Yudong Zhang ◽  
Claude Esling ◽  
Xiang Zhao ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Backscatter Diffraction ◽  
Type I ◽  
Type Ii ◽  
Plate Interface ◽  
Modulated Structure ◽  
Austenite Grain ◽  
Twinning Plane ◽  
Backscatter Diffraction ◽  
Comprehensive Study

A comprehensive study on the crystal structure, the microstructure and the crystallographic features of the martensite in an Ni50Mn38Sn12alloy 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 planeK1. 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.

Compare the Petrophysics of Formation Type I and II by Mercury Injection Curve Normalization

2014 ◽  
Vol 960-961 ◽  
pp. 258-261
Author(s):  
Ling Yun Chen ◽  
Yi Kun Liu ◽  
Li Hua Xia ◽  
Qian Liu
Keyword(s):  
Capillary Pressure ◽  
Thin Layers ◽  
Type I ◽  
Type Ii ◽  
Visual Identification ◽  
Mercury Injection ◽  
Order Of Magnitude ◽  
Formation Type ◽  
Capillary Pressure Curves ◽  
Developing Method

Study on Formation Type II is so few that affect on tapping the potential [2]. Analyzing petrophysics of Formation Type I and II by mercury injection curve normalization, it’s vital to developing method choice on tapping the potential of Formation Type II. Capillary pressure curves (Pc-curves) from conventional Mercury Injection are hard to analyze and compare because of various shapes. To get typical capillary pressure curves for Formation Type I and II, the curves from Mercury Injection is processed by Function J, and the J function curves and normalized Pc-curves for tabulated thin layers, tabulated thick layers and un-tabulated layers in Formation Type I and II, compare and analyze the influence of permeability on the shape of J function curves and normalized Pc-curves; compare the influence of different kinds of layers with the same permeability order of magnitude on the shape of J function curves and normalized Pc-curves, i.e. the influence of other factors except permeability, to get some visual identification methods and analyze the petrophysics difference between Formation Type I and II which is shown on Pc-curves.

scholarly journals Anisotropic Shape-Memory Alginate Scaffolds Functionalized with Either Type I or Type II Collagen for Cartilage Tissue Engineering

2017 ◽  
Vol 23 (1-2) ◽  
pp. 55-68 ◽  
Author(s):  
Henrique V. Almeida ◽  
Binulal N. Sathy ◽  
Ivan Dudurych ◽  
Conor T. Buckley ◽  
Fergal J. O'Brien ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Shape Memory ◽  
Cartilage Tissue Engineering ◽  
Type Ii Collagen ◽  
Cartilage Tissue ◽  
Type I ◽  
Type Ii

Determination of Preferred Morphology of Self-Accommodating Martensite in Ti-Nb-Al Shape Memory Alloy Using Optical Microscopy

2014 ◽  
Vol 922 ◽  
pp. 260-263 ◽  
Author(s):  
Masatoshi Ii ◽  
Masaki Tahara ◽  
Hideki Hosoda ◽  
Shuichi Miyazaki ◽  
Tomonari Inamura
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Optical Microscopy ◽  
Early Stage ◽  
Type I ◽  
Type Ii ◽  
Different Types ◽  
Forward Transformation

The preferred morphology of self-accommodation (SA) microstructure in a Ti-Nb-Al shape memory alloy was investigated by the evaluation of the frequency distribution of the habit plane variant (HPV) clusters using in-situ optical microscopy. The observed HPV clusters were classified into two different types; one is the cluster connected by the {111}o type I twin (Type I) and the other is connected by the <211>o type II twin (Type II). The total fractions of the Type I and Type II clusters were 52% and 48%, respectively. The incompatibility at junction planes (JPs) of the two clusters was almost the same among these clusters. However, most of the larger martensite plates (> 50μm) formed Type I cluster at the later stage of the reverse martensitic transformation, i.e., at the early stage of the forward transformation upon cooling. The ratio of the fraction of Type I and II is almost 2:1 at the early stage of the forward transformation.

EBSD-Based Crystallographic Study on a Ni-Mn-Ga Alloy with Incommensurate 7M Structure

2011 ◽  
Vol 702-703 ◽  
pp. 530-535
Author(s):  
Zong Bin Li ◽  
Yu Dong Zhang ◽  
Claude Esling ◽  
Xiang Zhao ◽  
Liang Zuo
Keyword(s):  
Martensite Transformation ◽  
Type I ◽  
Type Ii ◽  
Orientation Relationships ◽  
Twin Interface ◽  
Crystallographic Study ◽  
Austenite Grains ◽  
Parent Austenite ◽  
Martensitic Variants

Our recent work on EBSD-based characterization of incommensurate 7M modulated martensite in a polycrystalline Ni50Mn30Ga20alloy were summarized. The 7M martensitic plates were revealed to be self-accommodated in colonies, where each colony consisted of four types of variants that were twin related. All the pairs of variants can be categorized into three twinning modes, i.e. type-I, type-II and compound twins. The twin interface planes were in coincidence with the respective twinning planes. Using the measured orientations of adjacent martensitic variants, the orientations of parent austenite grains were calculated under the assumed orientation relationships for the austenite to martensite transformation. The energetically favorable orientation relationship between austenite and martenstie for the martensitic transformation was identified to be the Pitsch relation.

Structure and synthesis of the peritrophic membrane in Trichoptera larvae

Zoosymposia ◽  
2011 ◽  
Vol 5 (1) ◽  
pp. 63-70
Author(s):  
CARLA CORALLINI
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cardiac Valve ◽  
Food Type ◽  
Peritrophic Membrane ◽  
Type I ◽  
Type Ii ◽  
Food Ingestion ◽  
Transmission Electron ◽  
Anterior Midgut

The peritrophic membrane (PM) in Trichoptera larvae was examined by light, scanning and transmission electron microscopy. The gut of most insects produces 2 fundamental types of PM: Type I is synthesized and secreted by the entire midgut epithelium in response to the ingestion of food; type II is synthesized by specialized cells of the cardiac valve located in the anterior midgut independent from food ingestion. Corallini (2003) described, in the midgut of Limnephilidae larvae, a type I PM which is also secreted by unfed larvae. In this study, both types of PM were observed. Type I PM was evident in larvae of Rhyacophilidae, Leptoceridae, Sericostomatidae and Odontoceridae; the type II PM was observed in larvae of Philopotamidae, Polycentropodidae and Hydropsychidae.

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