High-pressure torsion of TiFe intermetallics for activation of hydrogen storage at room temperature with heterogeneous nanostructure

Edalati, Kaveh; Matsuda, Junko; Iwaoka, Hideaki; Toh, Shoichi; Akiba, Etsuo; Horita, Zenji

doi:10.1016/j.ijhydene.2013.01.185

Cited by 133 publications

(55 citation statements)

References 47 publications

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“…This problem can be eliminated when TiFe is preprocessed by HPT (Fig. 8) 97 or by other SPD techniques because hydrogen diffusion is facilitated through the introduction of a high density of microcracks and grain boundaries. Furthermore, the HPT-processed sample is not deactivated even after storage in air.…”

Section: Spd-processed Hydrogen Storage Materialsmentioning

confidence: 99%

Producing Bulk Ultrafine-Grained Materials by Severe Plastic Deformation: Ten Years Later

Valiev

Estrin

Horita

et al. 2016

JOM

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394

186

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It is now well established that the processing of bulk solids through the application of severe plastic deformation (SPD) leads to exceptional grain refinement to the submicrometer or nanometer level. Extensive research over the last decade has demonstrated that SPD processing also produces unusual phase transformations and leads to the introduction of a range of nanostructural features, including nonequilibrium grain boundaries, deformation twins, dislocation substructures, vacancy agglomerates, and solute segregation and clustering. These many structural changes provide new opportunities for fine tuning the characteristics of SPD metals to attain major improvements in their physical, mechanical, chemical, and functional properties. This review provides a summary of some of these recent developments. Special emphasis is placed on the use of SPD processing in achieving increased electrical conductivity, superconductivity, and thermoelectricity, an improved hydrogen storage capability, materials for use in biomedical applications, and the fabrication of high-strength metal-matrix nanocomposites.

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Section: Spd-processed Hydrogen Storage Materialsmentioning

confidence: 99%

Producing Bulk Ultrafine-Grained Materials by Severe Plastic Deformation: Ten Years Later

Valiev

Estrin

Horita

et al. 2016

JOM

Self Cite

394

186

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“…[112][113][114][115][116][117][118][119][120] Recent studies have shown that SPD processing is the way to achieve that, as such an activation process is no longer required when the TiFe is pre-processed by HPT ( Figure 15). [121] Furthermore, the HPT-processed sample is not deactivated even after storage in air for a prolonged period of time. [122] The mechanism enabling hydride formation without activation is associated with enhanced diffusion of hydrogen that occurs via HPTinduced microcracks and nanograin boundaries.…”

Section: Mg and Mgmentioning

confidence: 99%

Fundamentals of Superior Properties in Bulk NanoSPD Materials

Valiev

Estrin

Horita

et al. 2015

Materials Research Letters

296

136

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Bulk nanoSPD materials are materials with nanostructural features, such as nanograins, nanoclusters, or nanotwins, produced by severe plastic deformation (SPD) techniques. Such nanostructured materials are fully dense and contamination free and in many cases they have superior mechanical and functional properties. Here, we provide a critical overview of such materials, with a focus on the fundamentals for the observed extraordinary properties. We discuss the unique nanostructures that lead to the superior properties, the underlying deformation mechanisms, the critical issues that remain to be investigated, future research directions, and the application potential of such materials.

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“…[4][5][6][7][8][9][10] It is well known that the grain refinement to the submicrometer and/or nanometer range is achieved using the process of severe plastic deformation (SPD). [11] Although several processes are available for the SPD, [12,13] the process under high pressure, known as high-pressure torsion (HPT), [14][15][16] is effective for the grain refinement in hard and less ductile materials even such as intermetallics, [17][18][19][20][21][22] semiconductors, [23][24][25][26] and ceramics. [27,28] The sample for the HPT processing is used in a form of disk [14] or ring [29][30][31] and it may be extended to ribbons or wires if they are processed in a continuous way using continuous HPT (CHPT).…”

mentioning

confidence: 99%

Scaling up of High-Pressure Sliding (HPS) for Grain Refinement and Superplasticity

Takizawa

Masuda

Fujimitsu

et al. 2016

Metall Mater Trans A

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The process of high-pressure sliding (HPS) is a method of severe plastic deformation developed recently for grain refinement of metallic materials under high pressure. The sample for HPS is used with a form of sheet or rod. In this study, an HPS facility with capacities of 500 tonnes for vertical pressing and of 500 and 300 tonnes for horizontal forward and backward pressings, respectively, was newly built and applied for grain refinement of a Mg alloy as AZ61, Al alloys such as Al-Mg-Sc, A2024 and A7075 alloys, a Ti alloy as ASTM-F1295, and a Ni-based superalloy as Inconel 718. Sheet samples with dimensions of 10 to 30 mm width, 100 mm length, and 1 mm thickness were processed at room temperature and ultrafine grains with sizes of~200 to 300 nm were successfully produced in the alloys. Tensile testing at elevated temperatures confirmed the advent of superplasticity with total elongations of more than 400 pct in all the alloys. It is demonstrated that the HPS can make all the alloys superplastic through processing at room temperature with a form of rectangular sheets.

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High-pressure torsion of TiFe intermetallics for activation of hydrogen storage at room temperature with heterogeneous nanostructure

Cited by 133 publications

References 47 publications

Producing Bulk Ultrafine-Grained Materials by Severe Plastic Deformation: Ten Years Later

Producing Bulk Ultrafine-Grained Materials by Severe Plastic Deformation: Ten Years Later

Fundamentals of Superior Properties in Bulk NanoSPD Materials

Scaling up of High-Pressure Sliding (HPS) for Grain Refinement and Superplasticity

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