Abstract
The theory of the kinetics of phase change is developed with the experimentally supported assumptions that the new phase is nucleated by germ nuclei which already exist in the old phase, and whose number can be altered by previous treatment. The density of germ nuclei diminishes through activation of some of them to become growth nuclei for grains of the new phase, and ingestion of others by these growing grains. The quantitative relations between the density of germ nuclei, growth nuclei, and transformed volume are derived and expressed in terms of a characteristic time scale for any given substance and process. The geometry and kinetics of a crystal aggregate are studied from this point of view, and it is shown that there is strong evidence of the existence, for any given substance, of an isokinetic range of temperatures and concentrations in which the characteristic kinetics of phase change remains the same. The determination of phase reaction kinetics is shown to depend upon the solution of a functional equation of a certain type. Some of the general properties of temperature-time and transformation-time curves, respectively, are described and explained.
Keywords
KineticsPhase (matter)ThermodynamicsChemistryRange (aeronautics)Volume (thermodynamics)Transformation (genetics)Chemical physicsMaterials sciencePhysicsClassical mechanicsOrganic chemistry
Affiliated Institutions
Related Publications
Molecular dynamics simulations at constant pressure and/or temperature
In the molecular dynamics simulation method for fluids, the equations of motion for a collection of particles in a fixed volume are solved numerically. The energy, volume, and n...
Free Energy of a Nonuniform System. I. Interfacial Free Energy
It is shown that the free energy of a volume V of an isotropic system of nonuniform composition or density is given by : NV∫V [f0(c)+κ(▿c)2]dV, where NV is the number of molecul...
The 1994 Alcan Award Lecture Density functional theory as a practical tool in studies of organometallic energetics and kinetics. Beating the heavy metal blues with DFT
An evaluation is given of approximate density functional theory as a practical tool in studies on organometallic energetics and kinetics. The evaluation covers electronic excita...
First-principles calculations of the ferroelastic transition between rutile-type and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>CaCl</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>-type<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mtext>SiO</mml:mtext></mml:mrow><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>at high pressures
The tetragonal to orthorhombic ferroelastic phase transition between rutile- and CaCl2-type SiO2 at high pressures is studied using first-principles calculations and the Landau ...
Computer-Simulation Dynamics of an Unstable Two-Dimensional Fluid: Time-Dependent Morphology and Scaling
From an isothermal molecular-dynamics experiment of an unstable two-dimensional fluid undergoing phase separation, two principal growth regimes are observed: (1) spinodal decomp...
Publication Info
- Year
- 1939
- Type
- article
- Volume
- 7
- Issue
- 12
- Pages
- 1103-1112
- Citations
- 11004
- Access
- Closed
External Links
Social Impact
Altmetric
PlumX Metrics
Social media, news, blog, policy document mentions
Citation Metrics
11004
OpenAlex
Cite This
Melvin Avrami
(1939).
Kinetics of Phase Change. I General Theory.
The Journal of Chemical Physics
, 7
(12)
, 1103-1112.
https://doi.org/10.1063/1.1750380
Identifiers
- DOI
- 10.1063/1.1750380