Related Experiment Videos
High-resolution measurements of pressure solution creep
Dag Kristian Dysthe1, Francois Renard, Jens Feder
1Physics of Geological Processes, P.O. Box 1048, Blindern, N-0316 Oslo, Norway. d.k.dysthe@fys.uio.no
Summary
High-precision dilatometers measured indentation into sodium chloride, revealing pressure solution creep. Indentation rates showed strong history dependence, decreasing significantly over time.
Area of Science:
- Geophysics
- Materials Science
- Physical Chemistry
Background:
- Pressure solution creep is a key deformation mechanism in geological materials.
- Understanding indentation behavior is crucial for material science applications.
Purpose of the Study:
- To develop high-precision dilatometers for measuring indentation creep.
- To investigate the mechanism and kinetics of pressure solution creep in sodium chloride.
Main Methods:
- Developed and utilized two high-precision dilatometers.
- Measured indentation of gold wires and glass cylinders into sodium chloride.
- Analyzed indentation curves for history dependence and rate changes.
Main Results:
- Achieved indentation measurement accuracy down to 10 Angstroms and 6% precision.
- Observed a three-order-of-magnitude decrease in indentation rate over 400 hours.
- Identified pressure solution creep as the dominant indentation mechanism, involving dissolution and precipitation.
- Demonstrated that temperature and normal stress variations significantly impact indentation rates.
Conclusions:
- The study elucidates the pressure solution creep mechanism in sodium chloride under indentation.
- A time-dependent contact size model explains the observed history dependence.
- Indentation rates are primarily governed by dissolution kinetics rather than precipitation or plastic deformation.