scholarly journals Dislocation and diffusion creep of synthetic anorthite aggregates

2000 ◽  
Vol 105 (B11) ◽  
pp. 26017-26036 ◽  
Author(s):  
E. Rybacki ◽  
G. Dresen
Keyword(s):  
Diffusion Creep ◽  
And Diffusion

scholarly journals Ductile saline ice

1994 ◽  
Vol 40 (136) ◽  
pp. 566-568
Author(s):  
G. A. Kuehn ◽  
E. M. Schulson
Keyword(s):  
Fresh Water ◽  
Tensile Ductility ◽  
Compressive Deformation ◽  
Dislocation Creep ◽  
Diffusion Creep ◽  
Water Ice ◽  
The Matrix ◽  
And Diffusion

AbstractExperiments have shown that tensile ductility of about 5% or more can be imparted to columnar, saline ice by pre-compressing the material by about 3.5%. This effect is similar to that observed in granular, fresh-water ice and is attributed to the operation of both dislocation creep and diffusion creep within that part of the matrix which recrystallized during the pre-compressive deformation.

scholarly journals A unifying basis for the interplay of stress and chemical processes in the Earth: support from diverse experiments

2020 ◽  
Vol 175 (12) ◽  
Author(s):  
John Wheeler
Keyword(s):  
Chemical Potential ◽  
Chemical Processes ◽  
Phase Changes ◽  
Solid State Reactions ◽  
Fundamental Aspect ◽  
Diffusion Creep ◽  
Pressure Solution ◽  
Polymorphic Transformations ◽  
The Earth ◽  
And Diffusion

AbstractThe interplay between stress and chemical processes is a fundamental aspect of how rocks evolve, relevant for understanding fracturing due to metamorphic volume change, deformation by pressure solution and diffusion creep, and the effects of stress on mineral reactions in crust and mantle. There is no agreed microscale theory for how stress and chemistry interact, so here I review support from eight different types of the experiment for a relationship between stress and chemistry which is specific to individual interfaces: (chemical potential) = (Helmholtz free energy) + (normal stress at interface) × (molar volume). The experiments encompass temperatures from -100 to 1300 degrees C and pressures from 1 bar to 1.8 GPa. The equation applies to boundaries with fluid and to incoherent solid–solid boundaries. It is broadly in accord with experiments that describe the behaviours of free and stressed crystal faces next to solutions, that document flow laws for pressure solution and diffusion creep, that address polymorphic transformations under stress, and that investigate volume changes in solid-state reactions. The accord is not in all cases quantitative, but the equation is still used to assist the explanation. An implication is that the chemical potential varies depending on the interface, so there is no unique driving force for reaction in stressed systems. Instead, the overall evolution will be determined by combinations of reaction pathways and kinetic factors. The equation described here should be a foundation for grain-scale models, which are a prerequisite for predicting larger scale Earth behaviour when stress and chemical processes interact. It is relevant for all depths in the Earth from the uppermost crust (pressure solution in basin compaction, creep on faults), reactive fluid flow systems (serpentinisation), the deeper crust (orogenic metamorphism), the upper mantle (diffusion creep), the transition zone (phase changes in stressed subducting slabs) to the lower mantle and core mantle boundary (diffusion creep).

On the transition between dislocation and diffusion creep

1980 ◽  
Vol 41 (6) ◽  
pp. 871-882 ◽  
Author(s):  
G. W. Greenwood ◽  
H. Jones ◽  
T. Sritharan
Keyword(s):  
Diffusion Creep ◽  
And Diffusion

Plasticity and diffusion creep of dolomite

2008 ◽  
Vol 456 (3-4) ◽  
pp. 127-146 ◽  
Author(s):  
N.E. Davis ◽  
A.K. Kronenberg ◽  
J. Newman
Keyword(s):  
Diffusion Creep ◽  
And Diffusion

scholarly journals Ductile saline ice

1994 ◽  
Vol 40 (136) ◽  
pp. 566-568 ◽  
Author(s):  
G. A. Kuehn ◽  
E. M. Schulson
Keyword(s):  
Fresh Water ◽  
Tensile Ductility ◽  
Compressive Deformation ◽  
Dislocation Creep ◽  
Diffusion Creep ◽  
Water Ice ◽  
The Matrix ◽  
And Diffusion

AbstractExperiments have shown that tensile ductility of about 5% or more can be imparted to columnar, saline ice by pre-compressing the material by about 3.5%. This effect is similar to that observed in granular, fresh-water ice and is attributed to the operation of both dislocation creep and diffusion creep within that part of the matrix which recrystallized during the pre-compressive deformation.

Precipitates as Internal Markers for High Temperature Deformation Studies

1974 ◽  
Vol 32 ◽  
pp. 494-495
Author(s):  
K. Nuttall
Keyword(s):  
High Temperature ◽  
Grain Boundary Sliding ◽  
Dislocation Creep ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Diffusion Creep ◽  
Before And After ◽  
Probable Occurrence ◽  
Boundary Sliding ◽  
And Diffusion

A problem in the study of high temperature deformation mechanisms such as grain boundary sliding or diffusion creep is to obtain good metallographic evidence to demonstrate the probable occurrence of such processes. The difficulty arises because marked changes in microstructure such as those commonly observed after dislocation creep, e.g. grain elongation, sub-grain formation, changes in dislocation distribution, are not usually associated with sliding and diffusion creep so that microstructural comparisons before and after deformation are not too informative. Surface markers are frequently used as an indication of relative grain sliding and rotation, but there are separate difficulties in relating these observations to bulk behaviour.

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