scholarly journals Inversion of Nitrogen Redistribution in Austenitic Steel by Severe Plastic Deformation

2021 ◽  
Vol 122 (7) ◽  
pp. 657-664
Author(s):  
V. A. Shabashov ◽  
K. A. Lyashkov ◽  
N. V. Kataeva ◽  
L. G. Korshunov ◽  
V. V. Sagaradze ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Austenitic Steel ◽  
High Pressure Torsion ◽  
Temperature Limit ◽  
Complete Dissolution ◽  
Interstitial Solid Solution ◽  
Transmission Electron ◽  
Temperature Boundary ◽  
Nitrogen Redistribution

Abstract Using the Mössbauer spectroscopy and transmission electron microscopy (TEM) methods, the temperature boundary of a strain-induced transformation with the inversion of the direction of nitrogen redistribution is determined in the structure of the FeMn22Cr18N0.83 austenitic steel. Deformation by high pressure torsion in Bridgman anvils below the temperature limit (298 K) leads to an increase in the amount of nitrogen in the interstitial solid solution and deformation above the limit (373 K) leads to a decrease in this value. An increase in the deformation temperature leads to the complete dissolution of the products of cellular decomposition and the formation of submicrocrystalline austenite with secondary nanocrystalline nitrides. Changes in the direction of nitrogen redistribution are explained by the competition between the mechanisms of relaxation of the structure along the paths of dispersion, dissolution of nitrides by dislocation, and decomposition of a solid solution supersaturated with nitrogen.

scholarly journals Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

Transmission Electron Microscope Study of Interfacial Reactions in Gold-Germanium Contact to Gallium Arsenide

1985 ◽  
Vol 54 ◽  
Author(s):  
Taeil Kim ◽  
D.D.L. Chung
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Electron Microscope Study ◽  
Lattice Match ◽  
Perfect Lattice ◽  
Transmission Electron ◽  
Transmission Electron Microscope Study

ABSTRACTThe structure of 500 Å Au/500 A Ge/500 Å Au/GaAs (100) was studied by transmission electron microscopy after annealing at 350 – 500°C. Annealing at 350 – 450°C caused the formation of AuGeAs with a (110) texture, but this phase disappeared after annealing at 500°C. The hexagonal a-AuGa (or AuGa) was formed after annealing at 400°C, such that (111)Au // (0001)a, and [110]AU // [1120]a and there was perfect lattice match between Au (i.e., Au-rich solid solution) and a-AuGa. After annealing at 450°C or above, a phase tentatively identified as the hexagonal Au3Ga was formed and Ge (i.e., Ge-rich solid solution) became epitaxial to (100) GaAs. Annealing at 400°C caused Au to change from no texture to a (110) texture.

Orientation relationship and interfacial structure between Nbsolid solution precipitates and α-Nb5Si3 intermetallics

2009 ◽  
Vol 24 (1) ◽  
pp. 192-197 ◽  
Author(s):  
G.M. Cheng ◽  
Y.X. Tian ◽  
L.L. He
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Stress Concentration ◽  
High Resolution ◽  
Orientation Relationship ◽  
Interfacial Structure ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
High Resolution Tem

The orientation relationship (OR) and the interfacial structure between Nb solid solution (Nbss) precipitates and α-Nb5Si3 intermetallics have been investigated by transmission electron microscopy (TEM). The OR between Nbss and α-Nb5Si3 was determined by selected-area electron diffraction analyses as (222)Nb//(002)α and . High-resolution TEM images of the Nbss/α-Nb5Si3 interface were presented. Steps existed at the interface that acted as centers of stress concentration and released the distortion of lattices to decrease the interfacial energy. In addition, the interfacial models were proposed based on the observed OR to describe the atomic matching of the interface. The distribution of alloying elements at the Nbss/α-Nb5Si3 interface has also been investigated, and Hf was enriched at the interface to strengthen the grain boundary.

Nanoporous Ni and Ni-Cu Fabricated by Dealloying

2009 ◽  
Vol 1228 ◽  
Author(s):  
Masataka Hakamada ◽  
Yasumasa Chino ◽  
Mamoru Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Noble Metals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
The Difference ◽  
20 Nm ◽  
Good Workability ◽  
Scanning Electron

AbstractMetallic nanoporous architecture can be spontaneously attained by dealloying of a binary alloy. The nanoporous architecture can be often fabricated in noble metals such as Au and Pt. In this study, nanoporous Ni, Ni-Cu are fabricated by dealloying rolled Ni-Mn and Cu-Ni-Mn alloys, respectively. Unlike conventional Raney nickel composed of brittle Ni-Al or Cu-Al intermetallic compounds, the initial alloys had good workability probably because of their fcc crystal structures. After the electrolysis of the alloys in (NH4)2SO4 aqueous solution, nanoporous architectures of Ni and Ni-Cu with pore and ligament sizes of 10–20 nm were confirmed by scanning electron microscopy and transmission electron microscopy. X-ray diffraction analyses suggested that Ni and Cu atoms form a homogeneous solid solution in the Ni-Cu nanoporous architecture. The ligament sizes of nanoporous Ni and Ni-Cu were smaller than that of nanoporous Cu, reflecting the difference between diffusivities of Ni and Cu at solid/electrolyte interface. Ni can reduce the pore and ligament sizes of resulting nanoporous architecture when added to initial Cu-Mn alloys.

scholarly journals Formation of Au/Pd Alloy Nanoparticles on TMV

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Jung-Sun Lim ◽  
Seung-Min Kim ◽  
Sang-Yup Lee ◽  
Eric A. Stach ◽  
James N. Culver ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Genetically Engineered ◽  
Solid Solution Alloy ◽  
Alloy Formation ◽  
Alloy Nanoparticles ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Pd Alloy ◽  
Electron Energy Loss

A gold-palladium (AuPd) solid solution alloy was successfully deposited on the genetically engineered tobacco mosaic virus (TMV1Cys) by the biosorption of Au(III) and Pd(II) precursors and the reduction of the Au(III) and Pd(II) to their respective metals or metal alloy. The resulting morphologies of alloy nanoparticles deposited on the TMV1Cys were observed with transmission electron microscopy (TEM), and the AuPd alloy formation was supported with surface plasmon resonance (SPR) and selected area electron diffraction (SAED). In addition, selected alloy nanoparticles on the TMV1Cys were analyzed further with electron energy loss spectroscopy (EELS) to confirm the presence of gold and palladium. Our result implies that biotemplated metal mineralization is a potentially useful methodology to prepare alloy nanoparticles.

Synthesis of Nanocrystalline Ag-Cu Supersaturated Solid Solution by Mechanical Alloying

2010 ◽  
Vol 92 ◽  
pp. 271-276 ◽  
Author(s):  
Liang Feng Li ◽  
Tai Qiu ◽  
Jian Yang ◽  
Yong Bao Feng
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Mechanical Alloying ◽  
Solid Solutions ◽  
Supersaturated Solid Solution ◽  
Main Peak ◽  
Rich Phase ◽  
Transmission Electron ◽  
Supersaturated Solid Solutions ◽  
Xrd Patterns

Nanocrystalline Ag-28Cu supersaturated solid solution is prepared by mechanical alloying (MA) using a planetary ball mill. The mechanical alloyed powders are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and differential scanning calorimeter (DSC). XRD patterns show that the main peak of Ag-28Cu supersaturated solid solution exists at about 2θ=39° when the milling time is 30h. HRTEM images show that the grain sizes of as-prepared solid solutions have distributions from 10nm to 15nm. The interplanar spacing of (111) plane for fcc Ag-28Cu supersaturated solid solution is about 2.24Å. DSC measurement result indicates that the melting temperature of Ag-28Cu supersaturated solid solution is 783.8°C. The Ag(Cu) supersaturated solid solutions are in metastable state and they will be transformed into Ag-rich phase and Cu-rich phase simultaneously by annealing at 215°C- 415°C.

scholarly journals Эволюция микроструктуры и системы частиц Ti-=SUB=-3-=/SUB=-Ni-=SUB=-4-=/SUB=- при термообработках нанокристаллического сплава Ti-50.9 at.% Ni

2019 ◽  
Vol 89 (4) ◽  
pp. 534
Author(s):  
Т.М. Полетика ◽  
С.Л. Гирсова ◽  
А.И. Лотков ◽  
К.В. Круковский
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Nanocrystalline Alloy ◽  
Tini Alloy ◽  
Subgrain Structure ◽  
Solid Solution Decomposition ◽  
Transmission Electron

AbstractThe structure of a Ti−(50.9 at % Ni) nanocrystalline alloy is studied by transmission electron microscopy after annealing at 300−500°C. It is found that B2-TiNi solid solution decomposition according to a heterogeneous mechanism with formation of Ti_3Ni_4 particles develops in the subgrain structure and is suppressed in nanograins. The regularities of recovery, polygonization, and recrystallization in the grain/subgrain structure of a nanocrystalline TiNi alloy are established and their interconnection with processes of dissolution and coagulation of Ti_3Ni_4 particles is identified.

Epitaxially induced secondary grain growth in Ti:LiNbO3 optical waveguides

1989 ◽  
Vol 47 ◽  
pp. 424-425
Author(s):  
M. A. McCoy
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Transmission Electron Microscopy ◽  
Refractive Index ◽  
Lithium Niobate ◽  
Grain Growth ◽  
Optical Waveguides ◽  
Waveguide Devices ◽  
Transmission Electron ◽  
Electro Optic

Lithium niobate (LiNbO3) is one of the most promising materials for use in hybrid optical waveguide devices because of its high electro-optic coefficient and its availability as large single crystals. Optical waveguides in LiNbO3 are most commonly made by Ti indiffusion in which strips of Ti metal (between 10 and 100 nm thick) are deposited on a single crystal LiNbO3 substrate. The device is then heated to temperatures around 1000°C typically for 6 hours. During this time, the Ti diffuses into the LiNbO3 to form a Ti-rich LiNbO3 solid solution. This solid solution has a higher refractive index than the substrate and forms the waveguide region. Factors controlling the indiffusion process, however, are not very well understood and very little is known about the microstructural changes which occur during Ti indiffusion. In this study, the microstructure of Ti:LiNbO3 optical waveguides was examined as a function of time and temperature using transmission electron microscopy (TEM).

Microstructural Evolution in a CeO2-Gd2O3 System

2011 ◽  
Vol 18 (1) ◽  
pp. 162-170 ◽  
Author(s):  
Fei Ye ◽  
Ding Rong Ou ◽  
Toshiyuki Mori
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Microstructural Evolution ◽  
Oxygen Vacancies ◽  
Sudden Change ◽  
Fluorite Structure ◽  
Type Structure ◽  
Defect Clusters ◽  
Structured Matrix ◽  
Transmission Electron

AbstractMicrostructural evolution in a CeO2-Gd2O3 system at atomic and nanoscale levels with increasing Gd concentration has been comprehensively investigated by transmission electron microscopy. When the Gd concentration was increased from 10 to 80 at.%, the phase transformation from ceria with fluorite structure to solid solution with C-type structure was not a sudden change but an evolution in the sequence of clusters, domains, and precipitates with C-type structure in the fluorite-structured matrix. Moreover, the ordering of aggregated Gd cations and oxygen vacancies in these microstructural inhomogeneities developed continuously with increasing Gd concentration. This microstructural evolution can be further described based on the development of defect clusters containing Gd cations and oxygen vacancies.

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