Journal ArticleDOI
Nucleating heterogeneities and glass formation
TLDR
In this paper, the authors extended the kinetic treatment of glass formation by the introduction of continuous cooling (CT) curves to estimate the cooling rates required to form glasses of various materials.Abstract:
The kinetic treatment of glass formation is extended by the introduction of continuous cooling (CT) curves to estimate the cooling rates required to form glasses of various materials. The CT curves may be constructed from isothermal time-temperature-transformation curves following the approach originally suggested by Grange and Kiefer. The modified analysis is used to evaluate the effects of nucleating heterogeneities on glass formation. It is found that for the concentrations of such heterogeneities found in most liquids, those characterized by contact angles greater than about 100° have a negligible effect on the cooling rate required to form glasses. Heterogeneities with smaller contact angles, can, however, have a significant effect on glass formation, with the critical cooling rate increasing with decreasing contact angle. The effects on glass formation of changes in the contact angle of nucleating heterogeneities are also compared with the effects of changes in the thermodynamic barrier to nucleation (in the crystal-liquid surface energy).read more
Citations
More filters
Journal ArticleDOI
Models of the glass transition
TL;DR: A general survey of glass transition phenomena and concepts is presented in an introductory section as discussed by the authors, and the physical significance of computer simulations of glass transitions in simple liquids and the question of a hidden phase transition underlying an observed glass transition are examined critically.
Journal ArticleDOI
A classification system to assess the crystallization tendency of organic molecules from undercooled melts
TL;DR: The DSC screening method and classification scheme may be a useful tool to quickly assess the glass forming ability (GFA) and potential GS of new chemical entities during early drug development.
Journal ArticleDOI
Transient nucleation effects in glass formation
Kenneth F. Kelton,A.L. Greer +1 more
TL;DR: In this paper, a numerical technique was developed to treat transient homogeneous nucleation in a one-component system by modeling directly the reaction by which clusters are produced and calculated the nucleation frequency during quench and for the number of nuclei produced and the volume fraction transformed at the end of quench for different rates of cooling from the melt.
Journal ArticleDOI
Experimental tests of the classical nucleation theory for glasses
TL;DR: In this paper, Li2O·2SiO2 and barium disilicates were used to test the applicability of classical nucleation theory, and the experimentally determined preexponential factor A in the nucleation equation was much higher than the theoretical value, in agreement with previous studies.
References
More filters
Journal ArticleDOI
Granulation, Phase Change, and Microstructure Kinetics of Phase Change. III
TL;DR: In this paper, a comprehensive description of the phenomena of phase change may be summarized in Phase Change, Grain Number and Microstructure Formulas or Diagrams, giving, respectively, the transformed volume, grain, and microstructure densities as a function of time, temperature, and other variables.
Book
The theory of transformations in metals and alloys : an advanced textbook in physical metallurgy
Book
The theory of transformations in metals and alloys
J.W. Christian,H. M. Otte +1 more
TL;DR: In this paper, the authors present a general introduction to the theory of transformation kinetics of real metals, including the formation and evolution of martensitic transformations, as well as a theory of dislocations.
Journal ArticleDOI
A kinetic treatment of glass formation
TL;DR: In this article, a kinetic treatment of glass formation is presented, based on the construction of time-temperature-transformation curves corresponding to some barely detectable degree of crystallinity.