Modeling Solid-State Phase Transformations and Microstructure Evolution

MRS Bulletin ◽  
2001 ◽  
Vol 26 (3) ◽  
pp. 197-202 ◽  
Author(s):  
L.Q. Chen ◽  
C. Wolverton ◽  
V. Vaithyanathan ◽  
Z.K. Liu
Keyword(s):  
Solid State ◽  
Phase Transformations ◽  
Microstructure Evolution

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.

ChemInform Abstract: Modeling Solid-State Phase Transformations and Microstructure Evolution

ChemInform ◽  
2010 ◽  
Vol 32 (29) ◽  
pp. no-no
Author(s):  
L. Q. Chen ◽  
C. Wolverton ◽  
V. Vaithyanathan ◽  
Z. K. Liu
Keyword(s):  
Solid State ◽  
Phase Transformations ◽  
Microstructure Evolution

The use of high-resolution FESEM to study solid-state phase transformations and reactions

1994 ◽  
Vol 52 ◽  
pp. 1028-1029
Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Phase Transformations ◽  
High Efficiency ◽  
Sol Gel ◽  
Quantitative Information ◽  
Solid State Reactions ◽  
Critical Dimensions ◽  
Backscattered Electrons ◽  
Backscattered Electron

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.

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.

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