Superelastic behavior of in-situ eutectic-reaction manufactured high strength 3D porous NiTi-Nb scaffold

Abstract A eutectic reaction is a basic liquid-solid transformation, which can be used in the fabrication of high-strength in situ composites. In this study an attempt was made to ensure directional solidification of Fe-C-V alloy with hypereutectic microstructure. In this alloy, the crystallisation of regular fibrous eutectic and primary carbides with the shape of non-faceted dendrites takes place. According to the data given in technical literature, this type of eutectic is suitable for the fabrication of in-situ composites, owing to the fact that a flat solidification front is formed accompanied by the presence of two phases, where one of the phases can crystallise in the form of elongated fibres. In the present study an attempt was also made to produce directionally solidifying vanadium eutectic using an apparatus with a very high temperature gradient amounting to 380 W/cm at a rate of 3 mm/h. Alloy microstructure was examined in both the initial state and after directional solidification. It was demonstrated that the resulting microstructure is of a non-homogeneous character, and the process of directional solidification leads to an oriented arrangement of both the eutectic fibres and primary carbides.

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High-performance bulk Ti-Cu-Ni-Sn-Ta nanocomposites based on a dendrite-eutectic microstructure

Journal of Materials Research ◽

10.1557/jmr.2004.0332 ◽

2004 ◽

Vol 19 (9) ◽

pp. 2557-2566 ◽

Cited By ~ 34

Author(s):

Q.L. Dai ◽

B.B. Sun ◽

M.L. Sui ◽

G. He ◽

Y. Li ◽

...

Keyword(s):

High Performance ◽

Eutectic Reaction ◽

High Strength ◽

Eutectic Microstructure ◽

Reaction Products ◽

Transmission Electron ◽

Mold Casting ◽

High Resolution Tem ◽

Multi Phase

Using a Ti–Cu–Ni–Sn–Ta alloy as an example, we demonstrate a strategy for the in situ formation of nanocomposite microstructures that can lead to simultaneous high strength and ductility. Our approach employs copper mold casting for the production of bulk alloys from the melt, and the solidification microstructure is designed to be composed of micrometer-sized ductile dendrites uniformly distributed inside a matrix of nanoscale eutectic reaction products. The nanostructured matrix is achieved at a relatively deep eutectic, which facilitates the formation of an ultrafine eutectic microstructure over a range of cooling rates. The multi-component recipe stabilizes a ductile solid solution as the toughening phase and helps to reduce the eutectic spacing down to nanoscale. The multi-phase microstructure (including phase distributions, morphologies, and interfaces) has been examined in detail using transmission electron microscopy (TEM) and high-resolution TEM. The metastable eutectic reaction and the nanoscale spacing achieved are explained using thermodynamic and solidification modeling. The benefits expected from the microstructure design are illustrated using the high strength and large plasticity observed in mechanical property tests. Our nanocomposite design strategy is expected to be applicable to many alloy systems and constitutes another example of tailoring the microstructure on nanoscale for extraordinary properties.

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In situ observation of the martensitic transformation in (Mg,Y)-PSZ

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144036 ◽

1986 ◽

Vol 44 ◽

pp. 500-501

Author(s):

R-R. Lee

Keyword(s):

Martensitic Transformation ◽

High Strength ◽

Nucleation And Growth ◽

In Situ Observation ◽

Considerable Potential ◽

Transmission Electron ◽

Structural Applications ◽

Applied Stresses ◽

Kinetics Of

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.

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Radiation-initiated high strength chitosan/lithium sulfonate double network hydrogel/aerogel with porosity and stability for efficient CO2 capture

RSC Advances ◽

10.1039/d1ra03041h ◽

2021 ◽

Vol 11 (33) ◽

pp. 20486-20497

Author(s):

Zhiyan Liu ◽

Rui Ma ◽

Wenjie Du ◽

Gang Yang ◽

Tao Chen

Keyword(s):

Aqueous Solution ◽

High Strength ◽

Beam Radiation ◽

Chitosan Hydrogel ◽

Double Network ◽

Electron Beam Radiation ◽

Freeze Dried ◽

Urea Aqueous Solution ◽

Capture Capacity

Chitosan hydrogel is regenerated from alkali/urea aqueous solution and the lithium sulfonate second network is introduced by electron beam radiation-initiated in situ free radical polymerization. The freeze-dried aerogel has CO2 capture capacity.

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Rapid In Situ Polymerization of Polyacrylonitrile/Graphene Oxide Nanocomposites as Precursors for High-Strength Carbon Nanofibers

ACS Applied Materials & Interfaces ◽

10.1021/acsami.1c02643 ◽

2021 ◽

Author(s):

Ye Zhang ◽

Bo Zhu ◽

Xun Cai ◽

Xiaomin Yuan ◽

Shengyao Zhao ◽

...

Keyword(s):

Graphene Oxide ◽

Carbon Nanofibers ◽

In Situ Polymerization ◽

High Strength

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Mechanical Properties of Nanocrystalline Materials Produced by In Situ Consolidation Ball Milling

Materials Science Forum ◽

10.4028/www.scientific.net/msf.579.15 ◽

2008 ◽

Vol 579 ◽

pp. 15-28 ◽

Cited By ~ 8

Author(s):

Carl C. Koch ◽

Khaled M. Youssef ◽

Ron O. Scattergood

Keyword(s):

Mechanical Properties ◽

Ball Milling ◽

Nanocrystalline Materials ◽

Preparation Method ◽

High Strength ◽

Al Alloys ◽

Ductile Metals ◽

Cu Alloys ◽

Bulk Nanocrystalline

This paper reviews a method, “in situ consolidation ball milling” that provides artifactfree bulk nanocrystalline samples for several ductile metals such as Zn, Al and Al alloys, and Cu and Cu alloys. The preparation method is described in this paper and examples of the mechanical behavior of nanocrystalline materials made by this technique are given. It is found that in such artifact-free metals, combinations of both high strength and good ductility are possible.

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