Structure of silicon processed by severe plastic deformation

Исламгалиев, Р. К.; Kužel, R.; Mikov, S. N.; Igo, A. V.; Buriánek, Jiří; Chmelı́k, František; Valiev, Ruslan Z.

doi:10.1016/s0921-5093(99)00030-1

Cited by 57 publications

(21 citation statements)

References 13 publications

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“…These surface defects are also present on an as prepared por Si sample but have more clear boundaries and structure [5]. The as pre The average size of the 3C-SiC quantum dots forming on the surface of quantum silicon wires was estimated using Raman spectra [10]. It is interesting that the spectrum of SiC with a maximum at 970 cm -1 , which coincides with the position of the well known LO mode of silicon carbide [11], undergoes substantial changes during measurements, whereas the character istics of the silicon band remain unchanged.…”

Section: Experimental Results For the Carbonization Of Nanoporous Silmentioning

confidence: 99%

Thermodynamics of silicon carbide nucleation during the carbonization of nanoporous silicon

Nagornov

2015

Tech. Phys.

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A nucleation theory is proposed to describe the dynamics of formation of 3C-SiC nanocrystals during the carbonization of nanoporous silicon. A Monte Carlo simulation shows that spherical 3C-SiC nanocrystals form in quantum silicon wires in the first seconds, which coincides with the initial time of fusion of the pore walls. The energy barrier to silicon carbide nucleation is thermodynamically calculated, and the barrier is shown to be overcome due to a change in the pore wall area and, correspondingly, surface energy release. The proposed theory can be used to describe the necessary conditions of formation of 3C-SiC nanocrystals and explains why they do not form in single crystal silicon.

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Section: Experimental Results For the Carbonization Of Nanoporous Silmentioning

confidence: 99%

Thermodynamics of silicon carbide nucleation during the carbonization of nanoporous silicon

Nagornov

2015

Tech. Phys.

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“…[124] Because such high-pressure phases are semi-metallic in nature, they are more likely to deform plastically at room temperature under high pressure. An early study [125] and more recent studies [126,127] reported the formation of nanograins in crystalline Si processed by HPT. The mechanism for the nanograin formation is not understood but it is probably associated with enhanced dislocation activity or transformation-induced grain refinement.…”

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).…”

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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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Structure of silicon processed by severe plastic deformation

Cited by 57 publications

References 13 publications

Thermodynamics of silicon carbide nucleation during the carbonization of nanoporous silicon

Thermodynamics of silicon carbide nucleation during the carbonization of nanoporous silicon

Fundamentals of Superior Properties in Bulk NanoSPD Materials

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

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