scholarly journals Morphology and Kinetics Evolution of Nanoscale Phase in Fe–Cr Alloys under External Strain

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 294 ◽  
Author(s):  
Lihui Zhu ◽  
Yongsheng Li ◽  
Shujing Shi ◽  
Zhengwei Yan ◽  
Jing Chen ◽  
...  
Keyword(s):  
Phase Separation ◽  
Tensile Strain ◽  
Compressive Strain ◽  
Three Dimensional ◽  
Particle Number Density ◽  
Phase Region ◽  
Applied Strain ◽  
Uniaxial Tensile ◽  
Α Phase ◽  
Kinetics Of

Uniaxial strain was applied to aging Fe–Cr alloys to study the morphological orientation and kinetics of the nanoscale α′ phase by utilizing phase-field simulation. The effects of applied uniaxial compressive and tensile strain on the two and three-dimensional morphology as well as on the separation kinetics of the α′ phase are quantitatively clarified. Compared with the applied uniaxial tensile strain, the applied uniaxial compressive strain shows a greater effect on the rate of phase separation, lath shape morphology and an increased rate of growth and coarsening in the α′ phase, the boundary of the α + α′ phase region is widened influenced by the applied compressive strain, while the applied tensile strain results in an increase of particle number density and a decrease of particle radius. The peak value of particle size distribution of the α′ phase increases with aging time, while an opposite trend is shown under the applied strain, and there is an obvious deviation from the theoretical distribution of Lifshitz–Slyozov–Wagner under compressive strain. The orientation morphology and kinetic change show the substantial effects of applied strain on the phase separation and supplies the method for the morphological control of nanoscale particles.

Kinetics of the α-α′ phase separation in a 14%Cr oxide dispersion steel at intermediate temperatures

2020 ◽  
pp. 129088
Author(s):  
Yael Templeman ◽  
Malki Pinkas ◽  
Eli Brosh ◽  
Einat Strumza ◽  
Shmuel Hayun ◽  
...  
Keyword(s):  
Phase Separation ◽  
Oxide Dispersion ◽  
Α Phase ◽  
Kinetics Of

Required Linepipe Properties for High Strain Applications and Possible Resolution by Pipe Manufacturing Technology

2008 ◽  
Author(s):  
Hitoshi Asahi ◽  
Eiji Tsuru
Keyword(s):  
Tensile Strain ◽  
Compressive Strain ◽  
Bending Moment ◽  
Uniaxial Tensile ◽  
Buckling Behavior ◽  
Strain Limit ◽  
Bent Pipe ◽  
Uniaxial Tensile Stress ◽  
The Relationship ◽  
Pipe Manufacturing

Application of strain based design to pipelines in arctic or seismic areas has recently been recognized as important. So far, there has been much study performed on tensile strain limit and compressive strain limit. However, the relationship between bending buckling (compressive strain limit) and tensile strain limit has not been discussed. A model using actual stress strain curves suggests that the tensile strain limit increases as Y/T rises under uniaxial tensile stress because a pipe manufacturer usually raises TS instead of lowering YS to achieve low Y/T. Under bending of a pipe with a high D/t, an increase in compressive strain on intrados of a bent pipe at the maximum bending moment (ε-cp*) improves the tensile strain limit because the tensile strain limit is controlled by the onset of buckling or ε-cp* which is increased by lowering Y/T. On the other hand, under bending of a pipe with a low D/t, the tensile strain limit may not be influenced by improvement of buckling behavior because tensile strain on the extrados is already larger than the tensile limit at ε-cp*. Finally, we argue that the balance of major linepipe properties is important. Efforts other than the strict demands for pipe properties are also very important and inevitable to improve the strain capacity of a pipeline.

ATOMISTIC SIMULATION OF THE MECHANICAL BEHAVIOR OF Ni3Al NANOWIRES

2010 ◽  
Vol 24 (15) ◽  
pp. 1639-1645 ◽  
Author(s):  
DENGMU CHENG ◽  
SHENGJIE WANG ◽  
CHUNDONG WANG ◽  
ZHIGUO WANG
Keyword(s):  
Atomistic Simulation ◽  
Tensile Strain ◽  
Room Temperature ◽  
Elastic Limit ◽  
Uniform Elongation ◽  
Compressive Strain ◽  
Applied Strain ◽  
Simulation Results ◽  
Mechanism Of Failure ◽  
Elastic Stage

Simulations have been carried out on [001]-oriented Ni 3 Al nanowires with square cross-section with the purpose to investigate the mechanism of failure under tensile and compressive strain. Simulation results show that the elastic limit of the nanowire is up to about 15% strain with the yield stress of 5.99–6.48 GPa under tensile strain. Under the elastic stage, the deformation is carried mainly through the uniform elongation of the bonds between atoms. With more tensile strain, the slips in the {111} planes occur to accommodate the applied strain at room temperature under tensile strain. And the nanowires accommodate the compressive strain by forming the twins within the nanowires.

Remote Strain Measurement by Multi-Walled Carbon Nanotube-Dispersed Resin

2009 ◽  
Author(s):  
Katsuya Osaki ◽  
Hideki Fuji ◽  
Masato Onishi ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Strain Measurement ◽  
Tensile Strain ◽  
Axial Strain ◽  
Compressive Strain ◽  
Electronic Conductivity ◽  
Applied Strain ◽  
Dynamic Strain ◽  
Electric Resistance ◽  
Resistance Change ◽  
Base Materials

A new remote strain measurement method has been developed by applying the highly sensitive change of electronic conductivity of CNTs. Multi-walled CNTs were dispersed in various kinds of resins to form a thin film which can be attached rounded surfaces. The length of the CNTs was about a few μm. One of the base materials of resin employed was polycarbonate and the volumetric concentration of CNT dispersed was about 11.5%. The thickness of the film was about 500 μm. An uni-axial strain was applied to the CNT-dispersed resin by applying a 4 point bending method, and the change of the electric resistance was measured. The range of the applied strain was from −0.025% to 0.025%. The electric resistance changed almost linearly with the applied strain. The ratio of the resistance change under the tensile strain was about 40%/1000-μstrain and that under the compressive strain was about 15%/1000-μstrain. The micro wave of 99.5 GHz was irradiated to the CNT-dispersed polycarbonate film through the metallic prove 1 mm in diameter. The change of the intensity of the beam reflected from the film was measured by changing the amplitude of the uni-axial in-plane strain applied to the film. The intensity of the reflected beam increased almost linearly with the increase of the applied tensile strain and the change rate of the intensity was about 0.5%/1000-μstrain. This result clearly indicated that the surface dynamic strain can be detected by micro wave nondestructively and remotely.

scholarly journals Direct synthesis of highly stretchable ceramic nanofibrous aerogels via 3D reaction electrospinning

2021 ◽  
Author(s):  
Xiaota Cheng ◽  
Yang Si ◽  
Jianyong Yu ◽  
Bin Ding
Keyword(s):  
Thermal Stability ◽  
High Performance ◽  
Tensile Strain ◽  
Compressive Strain ◽  
Direct Synthesis ◽  
Extreme Environments ◽  
Three Dimensional ◽  
High Thermal Stability ◽  
High Porosity ◽  
Mechanical Performances

Abstract Ceramic aerogels are attractive for many applications due to their ultralow density, high porosity, and multifunctionalities but are limited by the typical trade-off relationship between mechanical properties and thermal stability when used in extreme environments. In this work, we designed and synthesized a unique ceramic nanofibrous aerogels with three-dimensional (3D) interwoven crimped-nanofibre structures that endow the aerogels with superior mechanical performances and high thermal stability. These ceramic aerogels were synthesized by a direct and facile route, 3D reaction electrospinning. They displayed robust structural stability with structure-derived mechanical ultra-stretchability up to 100% tensile strain and superior restoring capacity up to 40% tensile strain, 95% bending strain and 60% compressive strain, high thermal stability from -196 to 1400°C, repeatable stretchability at working temperatures up to 1300 ℃, and a low thermal conductivity of 0.0228 W m−1 K−1 in air. This work should enable the innovative design of high-performance ceramic aerogels for various applications.

Sub 50nm Strained n-FETs Formed on Silicon-Germanium-on-Insulator Substrates and the Integration of Silicon Source/Drain Stressors

2007 ◽  
Vol 995 ◽  
Author(s):  
Grace Huiqi Wang ◽  
Eng-Huat Toh ◽  
Keat-Mun Hoe ◽  
S. Tripathy ◽  
Guo-Qiang Lo ◽  
...  
Keyword(s):  
Performance Improvement ◽  
Silicon Germanium ◽  
Tensile Strain ◽  
Lattice Mismatch ◽  
Compressive Strain ◽  
Thin Body ◽  
Uniaxial Tensile ◽  
Silicon Source ◽  
D Region ◽  
And Performance

AbstractSilicon (Si) source and drain (S/D) regions have been successfully integrated in thin-body silicon-germanium-on-insulator (SGOI) n-FETs. The selectively grown Si S/D induces uniaxial tensile strain in the SiGe channel. Devices with gate length LG down to 50 nm were fabricated. The Si S/D gives rise to 40% higher saturation drive current IDsat for transistors fabricated on Si0.60Ge0.40-on-insulator substrates. For n-FETs fabricated on Si0.75Ge0.25-on-insulator substrates, a 27% IDsat enhancement was observed. Lattice mismatch between the silicon S/D region and the SiGe channel was exploited to induce lateral tensile strain and vertical compressive strain in the channel, leading to enhancement in electron mobility. Analyses of contributions from the tensile strain to mobility enhancement and performance improvement are discussed

scholarly journals Influence of Modulus of Base Layer on The Strain Distribution for Asphalt Pavement

2021 ◽  
Vol 16 (4) ◽  
pp. 126-152
Author(s):  
Kang Yao ◽  
Xin Jiang ◽  
Jin Jiang ◽  
Zhonghao Yang ◽  
Yanjun Qiu
Keyword(s):  
Strain Distribution ◽  
Tensile Strain ◽  
Asphalt Pavement ◽  
Compressive Strain ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Element Model ◽  
Neutral Axis ◽  
Base Layer ◽  
Maximum Tensile Strain

In order to investigate the influence of modulus of the base layer on the strain distribution for asphalt pavement, the modulus ratio of the base layer and the AC layer (Rm) is introduced as a controlled variable when keeping modulus of the AC layer as a constant in this paper. Then, a three-layered pavement structure is selected as an analytical model, which consists of an AC layer with the constant modulus and a base layer with the variable modulus covering the subgrade. A three dimensional (3D) finite element model was established to estimate the strains along the horizontal and vertical direction in the AC layer under different Rm. The results show that Rm will change the distribution of the horizontal strains along the depth in the AC layer; the increase of Rm could reduce the maximum tensile strain in the AC layer, but its effect is limited; the maximum tensile strain in the AC layer does not necessarily occur at the bottom, but gradually rises to the middle with the increase of Rm. Rm could significantly decline the bottom strain in the AC layer, and there is a certain difference between the bottom and the maximum strain when Rm is greater than or equal to one, which will enlarge with increasing Rm. Rm could change the depth of the neutral axis in the AC layer, and the second neutral axis will appear at the bottom of the AC layer under a sufficiently large Rm. The average vertical compressive strain in the AC layer will significantly enlarge with the increase of Rm.

The β'-α' Interaction: a Study of early Stages of Phase Separation in a Fe-20%Cr-6%Al-0.5%Ti Alloy

2011 ◽  
Vol 172-174 ◽  
pp. 315-320
Author(s):  
Carlos Capdevila ◽  
Michael K. Miller ◽  
K.F. Russell ◽  
J. Chao ◽  
F.A. López
Keyword(s):  
Phase Separation ◽  
Atom Probe Tomography ◽  
Temporal Evolution ◽  
Theoretical Calculations ◽  
Three Dimensional ◽  
Atom Probe ◽  
Early Stages ◽  
Β Phase ◽  
Α Phase ◽  
Power Measurements

The temporal evolution of the microstructure resulting from phase separation into Fe-rich (α), Cr-rich (α¢), and Fe(Ti,Al) (β¢) phases of a Fe-20Cr-6Al-0.5Ti alloy has been analyzed by thermoelectric power measurements (TEP). The early stages of decomposition and the evolution of the three-dimensional microstructure have been analyzed by atom probe tomography (APT). The roles of Cr, Al, and Ti during the decomposition process have been investigated in terms of solute partitioning between the phases. Analysis of proximity histograms revealed that significant Al and Ti partitioning occurs, which is consistent with theoretical calculations. The results indicate that as the α-α¢ phase separation proceeds, Al and Ti are rejected into the α phase, which causes the β¢ phase to nucleate on the surface of the α¢ phase.

Large Deformations of Low Density Open-Cell Elastomeric Foams: Kelvin Model Study

2011 ◽  
Vol 117-119 ◽  
pp. 550-555
Author(s):  
Qing Ping Zhang ◽  
Zhi Geng Fan
Keyword(s):  
Deformation Mechanism ◽  
Tensile Strain ◽  
Large Deformations ◽  
Compressive Strain ◽  
Uniaxial Tensile ◽  
Low Density ◽  
Kelvin Model ◽  
Open Cell ◽  
Model Study ◽  
Elastomeric Foams

Based on Kelvin model, the large deformations of elastomeric foams were simulated by finite element method (FEM). Numerical results indicated that edge bending, edge stretching and edge torsion were important deformation mechanisms of low density open-cell Kelvin foam. The hyperelasticity of the cell material had little effect on the macro-mechanical properties of the foam at low strain in [111] direction and finite compressive strain in [100] direction when edge bending was the main deformation mechanism of the foams. With the increase of the uniaxial tensile strain, edge stretching played notable roles, which resulted in that the hyperelasticity of the solid had significantly influence on the deformation of the foam at large uniaxial tensile strain. And the high strain compressive stress-strain curves in the [111] direction based on the hyperelastic relation differed from the linear elastic results remarkably as edge torsion was an important deformation mechanism of the foam.

High-resolution observations of metastable γ’ precipitation in Al-15at.%Ag

1996 ◽  
Vol 54 ◽  
pp. 1004-1005
Author(s):  
N. V. Larcher ◽  
I. G. Solorzano
Keyword(s):  
Discontinuous Precipitation ◽  
Equilibrium Phase ◽  
Quantitative Description ◽  
Present Contribution ◽  
Α Phase ◽  
The Matrix ◽  
Aging Sequence ◽  
Matrix Precipitation ◽  
Considerable Detail ◽  
Kinetics Of

It is currently well established that, for an Al-Ag alloy quenched from the α phase and aged within the metastable solvus, the aging sequence is: supersaturated α → GP zones → γ’ → γ (Ag2Al). While GP zones and plate-shaped γ’ are metastable phases, continuously distributed in the matrix, formation of the equilibrium phase γ takes place at grain boundaries by discontinuous precipitation (DP). The crystal structure of both γ’ and γ is hep with the following orientation relationship with respect to the fee α matrix: {0001}γ′,γ // {111}α, <1120>γ′,γ, // <110>α.The mechanisms and kinetics of continuous matrix precipitation (CMP) in dilute Al-Ag alloys have been studied in considerable detail. The quantitative description of DP kinetics, however, has received less attention. The present contribution reports the microstructural evolution resulting from aging an Al-Ag alloy with Ag content higher than those previously reported in the literature, focusing the observations of γ' plate-shaped metastable precipitates.

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