Characterization of NiTi and NiTiCu Porous Shape Memory Alloys Prepared by Powder Metallurgy (Part I)

Fe-14Mn-6Si-9Cr-5Ni (wt. %) shape memory alloys (SMAs) were produced by powder metallurgy (PM) combined with Mechanical Alloying (MA). The specimens were pressed and sintered under Ar atmosphere from as blended powders as well as from mixtures of as blended and 10, 20, 30 and 40 vol. % MA’ed powders, respectively. The five groups of sintered specimens were hot-rolled, spark-erosion cut and solution treated at five temperatures (923, 1023, …, 1373K/ 300 s/ water). Tensile loading-unloading tests were performed in order to obtain stress-induced martensite at different pre-straining degrees. The static responses of the twenty five types of specimens were evaluated by means of the surface areas under unloading curve (E2) and between loading and unloading curves (E1) which were used for determining static internal friction, Q-1. The dynamic responses of the undeformed specimens were determined by Dynamic Mechanical Analysis (DMA) performed at room temperature with a three-point-bending specimen holder in strain sweep mode. The structure of the twenty five specimens was analyzed X-ray diffraction. The effects of MA fraction were correlated with static and dynamic responses via structural changes.

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Electro-bending characterization of adaptive 3D fiber reinforced plastics based on shape memory alloys

Smart Materials and Structures ◽

10.1088/0964-1726/25/3/035041 ◽

2016 ◽

Vol 25 (3) ◽

pp. 035041 ◽

Cited By ~ 15

Author(s):

Moniruddoza Ashir ◽

Lars Hahn ◽

Axel Kluge ◽

Andreas Nocke ◽

Chokri Cherif

Keyword(s):

Shape Memory Alloys ◽

Shape Memory ◽

Fiber Reinforced ◽

Reinforced Plastics ◽

Fiber Reinforced Plastics

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On Analysis of DSC Curves for Characterization of Intrinsic Properties of NiTi Shape Memory Alloys

Acta Physica Polonica A ◽

10.12693/aphyspola.122.601 ◽

2012 ◽

Vol 122 (3) ◽

pp. 601-605 ◽

Cited By ~ 3

Author(s):

A. Ziółkowski

Keyword(s):

Shape Memory Alloys ◽

Shape Memory ◽

Intrinsic Properties ◽

Niti Shape Memory Alloys ◽

Dsc Curves

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A new approach to characterization of the transition temperatures of thin film NiTi shape memory alloys

Journal of Materials Research ◽

10.1557/jmr.2004.0240 ◽

2004 ◽

Vol 19 (6) ◽

pp. 1762-1767

Author(s):

Nicholas W. Botterill ◽

David M. Grant ◽

Jianxin Zhang ◽

Clive J. Roberts

Keyword(s):

Thin Film ◽

Shape Memory Alloys ◽

Shape Memory ◽

Transition Temperatures ◽

New Approach ◽

Novel Approach ◽

Potential Applications ◽

Niti Shape Memory Alloys

A novel approach in determining the transition temperatures of NiTi shape memory alloys was investigated and compared with conventional techniques. The technique is based on microthemal analysis using a scanning thermal microscope (SThM). In particular, this method has the potential to allow the transformation temperatures of thin films to be investigated in situ. Thin film shape memory alloys have potential applications, such as microactuators, where conventional analysis techniques are either not directly applicable to such samples or are difficult to perform.

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The Influence of α′ (bcc) Martensite on the Dynamic and Magnetic Response of Powder Metallurgy FeMnSiCrNi Shape Memory Alloys

Proceedings of the International Conference on Martensitic Transformations: Chicago - The Minerals, Metals & Materials Series ◽

10.1007/978-3-319-76968-4_16 ◽

2018 ◽

pp. 99-108 ◽

Cited By ~ 1

Author(s):

M. Mocanu ◽

E. Mihalache ◽

B. Pricop ◽

F. Borza ◽

M. Grigoraș ◽

...

Keyword(s):

Powder Metallurgy ◽

Shape Memory Alloys ◽

Shape Memory ◽

Magnetic Response

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Mechanics of nickel–titanium shape memory alloys undergoing partially constrained recovery for self-healing materials

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x18781260 ◽

2018 ◽

Vol 29 (15) ◽

pp. 3025-3036 ◽

Cited By ~ 2

Author(s):

Nathan Salowitz ◽

Ameralys Correa ◽

Trishika Santebennur ◽

Afsaneh Dorri Moghadam ◽

Xiaojun Yan ◽

...

Keyword(s):

Shape Memory Alloys ◽

Shape Memory ◽

Nickel Titanium ◽

Self Healing ◽

Bonding Agents ◽

Compressive Loads ◽

Martensitic State ◽

Geometric Changes ◽

Shape Memory Fibers

Engineered self-healing materials seek to create an innate ability for materials to restore mechanical strength after incurring damage, much like biological organisms. This technology will enable the design of structures that can withstand their everyday use without damage but also recover from damage due to an overload incident. One of the primary mechanisms for self-healing is the incorporation of shape memory fibers in a composite type structure. Upon activation, these shape memory fibers can restore geometric changes caused by damage and close fractures. To date, shape memory–based self-healing, without bonding agents, has been limited to geometric restoration without creating a capability to withstand externally applied tensile loads due to the way the shape memory material has been integrated into the composite. Some form of bonding has been necessary for self-healing materials to resist an externally applied load after healing. This article presents results of new study into using a form of constrained recovery of nickel–titanium shape memory alloys in self-healing materials to create residual compressive loads across fractures in the low temperature martensitic state. Analysis is presented relating internal loads in self-healing materials, potentially generated by shape memory alloys, to the capability to resist externally applied loads. Supporting properties were experimentally characterized in nickel–titanium shape memory alloy wires. Finally, self-healing samples were synthesized and tested demonstrating the ability to resist externally applies loads without bonding. This study provides a new useful characterization of nickel–titanium applicable to self-healing structures and opens the door to new forms of healing like incorporation of pressure-based bonding.

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