Metamorphism as Garnet Sees It: The Kinetics of Nucleation and Growth, Equilibration, and Diffusional Relaxation

Elements ◽  
2013 ◽  
Vol 9 (6) ◽  
pp. 439-445 ◽  
Author(s):  
J. J. Ague ◽  
W. D. Carlson
Author(s):  
R-R. Lee

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.


2000 ◽  
Vol 650 ◽  
Author(s):  
S. L. Dudarev

ABSTRACTThe effect of inhomogeneous nucleation and growth of cavities near grain boundaries illustrates the failure of the standard rate theory to describe the kinetics of phase transformations in irradiated materials under cascade damage conditions. The enhanced swelling observed near grain boundaries is believed to result from the competition between the diffusional growth of cavities and their shrinkage due to the interaction with mobile interstitial clusters. Swelling rates associated with the two processes behave in a radically different way as a function of the size of growing cavities. For a spatially homogeneous distribution of cavities this gives rise to the saturation of swelling in the limit of large irradiation doses.We investigate the evolution of the population of cavities nucleating and growing near a planar grain boundary. We show that a cavity growing near the boundary is able to reach a size that is substantially larger than the size of a cavity growing in the interior region of the grain. For a planar grain boundary the magnitude of swelling at maximum is found to be up to eight times higher than the magnitude of swelling in the grain interior.


2013 ◽  
Vol 378 ◽  
pp. 115-120 ◽  
Author(s):  
I. Dyamant ◽  
A.S. Abyzov ◽  
V.M. Fokin ◽  
E.D. Zanotto ◽  
J. Lumeau ◽  
...  

1987 ◽  
Vol 115 (2) ◽  
pp. 372-377 ◽  
Author(s):  
L Durai ◽  
R Dhanasekaran ◽  
P Ramasamy

2011 ◽  
Vol 317-319 ◽  
pp. 42-47
Author(s):  
Li Fang Zhang ◽  
Yong Chang Liu

By fitting the calculated transformed fraction according to developed phase-transformation model to the experimental data obtained by differential dilatometry, the kinetic characteristics of the austenitization process in T91 steels have been investigated. According to the kinetic parameters fitted, we recognize that the nucleation and growth of austenite grain are mainly controlled by the diffusion of carbon in ferritic and austenite respectively. In addition, by increasing the diffusion active energy of carbon in austenite, carbides hinder the motion of interface and thus refine austenite grain.


1994 ◽  
Vol 144 (3-4) ◽  
pp. 281-290 ◽  
Author(s):  
Amarjit J. Mahajan ◽  
Donald J. Kirwan

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1515
Author(s):  
Jonathan Alms ◽  
Christian Hopmann ◽  
Jian Wang ◽  
Tobias Hohlweck

The modelling of the correlation between pressure, specific volume and temperature (pvT) of polymers is highly important for applications in the polymer processing of semi-crystalline thermoplastics, especially in injection moulding. In injection moulding, the polymer experiences a wide range of cooling rates, for example, 60 °C/min near the centre of the part and up to 3000 °C/min near the mould walls. The cooling rate has a high influence on the pvT behaviour, as was shown in the continuous two-domain pvT model (CTD). This work examined the Hoffman–Lauritzen nucleation and growth theory used in the modified Hammami model for extremely high cooling rates (up to 300,000 °C/min) by means of Flash differential scanning calorimeter (DSC) measurements. The results were compared to those of the empirical continuous two-domain pvT model. It is shown that the Hammami model is not suitable to predict the crystallisation kinetics of polypropylene at cooling rates above 600 °C/min, but that the continuous two-domain pvT model is well able to predict crystallisation temperatures at high cooling rates.


2009 ◽  
Vol 26 (1) ◽  
pp. 175-181 ◽  
Author(s):  
Bogusława Wierzbowska ◽  
Krzysztof Piotrowski ◽  
Joanna Koralewska ◽  
Nina Hutnik ◽  
Andrzej Matynia

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