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Updated: Jul 3, 2026
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Stress Distribution During Cold Compression of Rocks and Mineral Aggregates Using Synchrotron-based X-Ray Diffraction
Published on: May 20, 2018
Stress, strain, and bulk microstructure in a cohesive powder
R Andersson1, W G Bouwman, S Luding
1Radiation, Radionuclides & Reactors, Delft University of Technology, Mekelweg 15, 2629JB Delft, The Netherlands. r.a..andersson@tudelft.nl
Summary
Spin-echo small-angle neutron scattering reveals how cohesive powders change under compression. Increasing stress leads to denser packing and rougher structures, linking microstructural changes to the powder’s overall mechanical behavior.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Neutron Scattering
Background:
- Cohesive powders exhibit complex microstructural behavior under mechanical stress.
- Understanding powder packing and its evolution is crucial for material performance.
Purpose of the Study:
- To investigate the microstructural evolution of fine cohesive powders during uniaxial compression.
- To correlate macroscopic mechanical properties with microscopic structural changes.
Main Methods:
- Utilizing spin-echo small-angle neutron scattering (SE-SAS) to probe powder microstructure.
- Measuring the density-density correlation function and its autocorrelation function.
- Analyzing the fractal dimension of powder packing as a function of applied stress.
Main Results:
- Quantified typical sizes of microstructural heterogeneities.
- Determined the fractal dimension of powder packing, observing an increase with stress.
- Observed nonlinear behavior in microscopic stress-strain relations mirroring macroscopic trends.
- Linked macroscopic compressive strain to a decrease in microstructural length scales.
Conclusions:
- The study successfully connected macroscopic mechanical response to microstructural evolution in cohesive powders.
- Increasing stress promotes denser packing and rougher phase boundaries, indicating a more space-filling structure.
- SE-SAS is an effective tool for characterizing powder microstructure and its response to mechanical loading.
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