scholarly journals Low-Voltage FIB/SEM Tomography for 3D Microstructure Evolution of LiFePO4/C Electrode

2015 ◽  
Vol 69 (18) ◽  
pp. 71-80 ◽  
Author(s):  
R. Scipioni ◽  
P. S. Jorgensen ◽  
D.-T. Ngo ◽  
S. B. Simonsen ◽  
J. Hjelm ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Low Voltage ◽  
3D Microstructure

scholarly journals QUANTITATIVE IMAGE ANALYSIS OF MICROSTRUCTURE EVOLUTION DURING SOLID STATE SINTERING OF W-Cu

2011 ◽  
Vol 21 (2) ◽  
pp. 133
Author(s):  
Ana Maria Popa ◽  
JeanMarc Chaix
Keyword(s):  
Solid State ◽  
Microstructure Evolution ◽  
Low Voltage ◽  
Initial Mixture ◽  
Surface Wetting ◽  
Careful Preparation ◽  
Quantitative Image ◽  
Solid State Sintering ◽  
Cu Migration

The microstructure evolution of W-Cu composites during solid state sintering at 1050°C is studied on samples quenched after different sintering times. The microstructure is formed by 3 phases: tungsten (W), copper (Cu) and pores. During the process, the initial mixture of W- and Cu-powder is transformed by migration of Cu and rearrangement of W particles. These microstructural changes are studied to identify the underlying phenomena and to control the material properties. Based on experiments performed with two different W powders, this paper deals with various aspects of the quantitative analysis of the observed evolution. A careful preparation of the images is necessary. The porous samples are impregnated with a resin under vacuum before being cut and carefully polished. Low voltage (<10 kV) is used during image acquisition on a scanning electron microscope. Area fraction measurements are used to check the quality of the images and the segmentation process. Classical measurements are used to study the spreading of Cu onto the surface of W particles: surface area of each phase, area of contact between phases, chord length distributions. New measurements based on classical methods are also developed to distinguish between two mechanisms of Cu migration in the microstructure : Cu spreading on W surface (wetting of the surface), and capillary penetration in the inter-W channels. An analysis of the location of Cu and pores in the space between W particles (inter-W space) is performed using a granulometry based on 2D openings. It evidences the mechanism of capillary penetration of Cu in the inter-W space in the case of small W-particles.

Three Dimensional Prediction of Microstructure Evolution and Mechanical Properties of Hot Strips

2011 ◽  
Vol 291-294 ◽  
pp. 455-464 ◽  
Author(s):  
Guo Ming Zhu ◽  
Chao Lv ◽  
Yong Lin Kang ◽  
Guo Guang Cheng
Keyword(s):  
Microstructure Evolution ◽  
Prediction Models ◽  
Computational Simulation ◽  
Temperature Drop ◽  
Three Dimensional ◽  
Rolling Process ◽  
Real Situation ◽  
Property Prediction ◽  
C Language ◽  
3D Microstructure

With the 3D thermal mechanical coupled elastic-plastic finite element method and by simulating the whole rolling process of 1250mm×20mm C-Mn hot strips, this paper obtains the temperature field and deformation result of the rolling process. By comparing the temperature drop curve with the measured data in the field, it shows that the simulation result is close to the real situation. Based on the thermal mechanical coupled simulation of the whole rolling process, this paper completes the computational simulation of the prediction of the 3D microstructure and property of hot strips by using the relevant microstructure evolution and property prediction models and advanced C language programming, thus providing reference for the property prediction of new products and processes.

Evolution of Individual Grains in 3d Microstructure Generated by Computational Simulation of Transformations Involving Two Phases

2018 ◽  
Vol 930 ◽  
pp. 305-310
Author(s):  
André Luiz Moraes Alves ◽  
Guilherme Dias da Fonseca ◽  
Marcos Felipe Braga da Costa ◽  
Weslley Luiz da Silva Assis ◽  
Paulo Rangel Rios
Keyword(s):  
Mathematical Model ◽  
Solid State ◽  
Phase Transformations ◽  
Microstructure Evolution ◽  
Initial Phase ◽  
Computational Simulation ◽  
3D Microstructure ◽  
Phase Transform ◽  
Two Phases ◽  
Individual Grains

In the phase transformations of the solid state, situations can occur in which the initial phase transform forming two or more distinct phases. The exact mathematical model for situations where more than one transformation occurs simultaneously or sequentially was proposed by Rios and Villa. The computational simulation was used to study the evolution and visualization of the possible microstructures that these transformations may present. The causal cone methodology was adopted. The simulations were compared with the analytical model to ensure that they occur as expected. The growth of individual grains of each phase was monitored in 3D microstructure evolution. With this monitoring, was possible to extract useful data able to quantify the simulated 3D microstructure. Quantifying the simulated microstructures increase the possibility of the simulations give to the experimentalist insights about the transformations. In this paper, it is verified that each grain evolves in an individual way, as expected, however their growth is similar.

scholarly journals Microstructure and mechanical properties of 3D Cf/SiBCN composites fabricated by polymer infiltration and pyrolysis

2020 ◽  
Author(s):  
Bowen Chen ◽  
Qi Ding ◽  
De-Wei Ni ◽  
Hongda Wang ◽  
Yusheng Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Cross Link ◽  
Ceramic Yield ◽  
Liquid Precursor ◽  
X Ray ◽  
3D Microstructure ◽  
Crosslinking Process ◽  
X Ray Computed ◽  
Polymer Infiltration

Abstract In this work, 3D Cf/SiBCN composites were fabricated by polymer infiltration and pyrolysis (PIP) with poly(methylvinyl)borosilazane as SiBCN precursor. The 3D microstructure evolution process of the composites was investigated by an advanced x-ray computed tomography (XCT). The effect of dicumyl peroxide (DCP) initiator addition on the crosslinking process, microstructure evolution and mechanical properties of the composites were uncovered. With the addition of DCP initiator, the liquid precursor can cross-link to solid-state at 120 °C. Moreover, DCP addition decreases the release of small molecule gas during pyrolysis, leading to an improved ceramic yield 4.67 times higher than that without DCP addition. After 7 PIP cycles, density and open porosity of the final Cf/SiBCN composite with DCP addition are 1.73 g·cm-3 and ~10%, respectively, which are 143.0% higher and 30.3% lower compared with the composite without DCP addition. As a result, the flexural strength and elastic modulus of Cf/SiBCN composites with DCP addition (371 MPa and 31 GPa) are 1.74 and 1.60 times higher than that without DCP addition (213 MPa and 19.4 GPa).

Simulation and experimental comparison of the thermo-mechanical history and 3D microstructure evolution of 304L stainless steel tubes manufactured using LENS

2017 ◽  
Vol 61 (5) ◽  
pp. 559-574 ◽  
Author(s):  
Kyle L. Johnson ◽  
Theron M. Rodgers ◽  
Olivia D. Underwood ◽  
Jonathan D. Madison ◽  
Kurtis R. Ford ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Microstructure Evolution ◽  
Experimental Comparison ◽  
304L Stainless Steel ◽  
Steel Tubes ◽  
3D Microstructure

scholarly journals Microstructure and mechanical properties of 3D Cf/SiBCN composites fabricated by polymer infiltration and pyrolysis

2020 ◽  
Author(s):  
Bowen Chen ◽  
Qi Ding ◽  
Dewei Ni ◽  
Hongda Wang ◽  
Yusheng Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Three Dimensional ◽  
Cross Linking ◽  
Ceramic Yield ◽  
X Ray ◽  
3D Microstructure ◽  
Crosslinking Process ◽  
X Ray Computed ◽  
Polymer Infiltration

AbstractIn this work, three-dimensional (3D) Cf/SiBCN composites were fabricated by polymer infiltration and pyrolysis (PIP) with poly(methylvinyl)borosilazane as SiBCN precursor. The 3D microstructure evolution process of the composites was investigated by an advanced X-ray computed tomography (XCT). The effect of dicumyl peroxide (DCP) initiator addition on the crosslinking process, microstructure evolution, and mechanical properties of the composites were uncovered. With the addition of a DCP initiator, the liquid precursor can cross-linking to solid-state at 120 °C. Moreover, DCP addition decreases the release of small molecule gas during pyrolysis, leading to an improved ceramic yield 4.67 times higher than that without DCP addition. After 7 PIP cycles, density and open porosity of the final Cf/SiBCN composite with DCP addition are 1.73 g·cm−3 and ∼10%, respectively, which are 143.0% higher and 30.3% lower compared with the composites without DCP addition. As a result, the flexural strength and elastic modulus of Cf/SiBCN composites with DCP addition (371 MPa and 31 GPa) are 1.74 and 1.60 times higher than that without DCP addition (213 MPa and 19.4 GPa), respectively.

scholarly journals Microstructure and mechanical properties of 3D Cf/SiBCN composites fabricated by polymer infiltration and pyrolysis

2020 ◽  
Author(s):  
Bowen Chen ◽  
Qi Ding ◽  
De-Wei Ni ◽  
Hongda Wang ◽  
Yusheng Ding ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Microstructure Evolution ◽  
Cross Link ◽  
Ceramic Yield ◽  
Liquid Precursor ◽  
X Ray ◽  
3D Microstructure ◽  
Crosslinking Process ◽  
X Ray Computed ◽  
Polymer Infiltration

Abstract In this work, 3D C f /SiBCN composites were fabricated by polymer infiltration and pyrolysis (PIP) with poly(methylvinyl)borosilazane as SiBCN precursor. The 3D microstructure evolution process of the composites was investigated by an advanced x-ray computed tomography (XCT). The effect of dicumyl peroxide (DCP) initiator addition on the crosslinking process, microstructure evolution and mechanical properties of the composites were uncovered. With the addition of DCP initiator, the liquid precursor can cross-link to solid-state at 120 °C. Moreover, DCP addition decreases the release of small molecule gas during pyrolysis, leading to an improved ceramic yield 4.67 times higher than that without DCP addition. After 7 PIP cycles, density and open porosity of the final Cf/SiBCN composite with DCP addition are 1.73 g·cm -3 and ~10%, respectively, which are 143.0% higher and 30.3% lower compared with the composites without DCP addition. As a result, the flexural strength and elastic modulus of Cf/SiBCN composites with DCP addition (371 MPa and 31 GPa) are 1.74 and 1.60 times higher than that without DCP addition (213 MPa and 19.4 GPa).

The Influence of Electric Current Pulses on the Microstructure of Magnesium Alloy AZ91D

2005 ◽  
Vol 488-489 ◽  
pp. 201-204 ◽  
Author(s):  
Yuan Sheng Yang ◽  
Quan Zhou ◽  
Zhuang Qi Hu
Keyword(s):  
Magnesium Alloy ◽  
Electric Current ◽  
Microstructure Evolution ◽  
Nucleation Rate ◽  
Low Voltage ◽  
Az91d Alloy ◽  
Current Pulses ◽  
Alloy Az91d ◽  
Electric Current Pulses ◽  
Semi Solid

The microstructure evolution of magnesium alloy AZ91D solidified with different electric current pulses and cooling rates was investigated and a new method, Low-voltage Electric Current Pulses (LVECP), to produce semi-slurry magnesium alloy was developed in this paper. The experimental results showed that the electric current pulses during solidification changed morphology of dendrites and the equiaxed, non-dendritic grains formed. The size of the primary a-Mg particles in semi-solid AZ91D alloy and the sphericity of the particles decreased with increase of discharging the voltage and treating time of LVECP. The increase of the cooling rate during the solidification of AZ91D alloy with LVECP promoted the formation of finer a-Mg particles, but the value of the sphericity of the particles rised. The formation of equiaxed, nondendritic structure by LVECP might be attributed to the electric current pulses increase the nucleation rate, restrained growth of the dendrites, and made dendrite arms remelted during the solidification of AZ91D alloy.

3D microstructure evolution of ice in jet A-1 fuel as a function of applied temperature over time

2021 ◽  
pp. 122158
Author(s):  
Iheb Haffar ◽  
Frédéric Flin ◽  
Christian Geindreau ◽  
Nicolas Petillon ◽  
Pierre-Colin Gervais ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
3D Microstructure ◽  
Over Time
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