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Updated: Jun 12, 2026
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Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples
Published on: June 19, 2018
Note: X-ray radiography for measuring chemical diffusion in metallic melts
A Griesche1, B Zhang, E Solórzano
1Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Linder Höhe, 51170 Köln, Germany. axel.griesche@bam.de
The Review of Scientific Instruments
|June 3, 2010
Summary
This study introduces an advanced X-ray radioscopy method for precise in situ measurement of chemical diffusion in metallic melts. The technique improves accuracy by distinguishing diffusion from convective flow, unlike traditional methods.
Area of Science:
- Materials Science
- Physical Chemistry
- Metallurgy
Background:
- Accurate measurement of chemical diffusion coefficients in metallic melts is crucial for understanding material properties and processes.
- Traditional methods like the long-capillary method with postmortem analysis have limitations in accuracy due to potential convective flow contributions.
- In situ monitoring of diffusion processes in real-time is challenging, especially in opaque metallic systems.
Purpose of the Study:
- To develop and validate a novel X-ray radioscopy technique for in situ measurement of chemical diffusion coefficients in metallic melts.
- To enhance the accuracy of diffusion measurements by enabling the separation of diffusive and convective mass transport.
- To demonstrate the technique's capability using a diffusion experiment in an Aluminum-Nickel (Al-Ni) melt.
Main Methods:
- Integration of a long-capillary diffusion measurement setup with advanced X-ray imaging using microfocus tubes and flat panel detectors.
- Real-time visualization and quantitative analysis of diffusive mixing between two metallic melts of different compositions.
- Application of Fick's diffusion laws and analysis of the time dependence of the mean square penetration depth to determine interdiffusion coefficients.
Main Results:
- The developed X-ray radioscopy technique successfully visualized and quantified the diffusive mixing process in situ.
- The method allowed for the determination of interdiffusion coefficients as a function of temperature and time.
- Tracking the penetration depth enabled the detection and subsequent exclusion of convective mass transport, significantly improving measurement accuracy.
Conclusions:
- The novel X-ray radioscopy technique offers a significant advancement for accurate in situ measurement of chemical diffusion in metallic melts.
- This method overcomes limitations of conventional techniques by effectively separating diffusion from convection.
- The demonstrated application in an Al-Ni melt highlights the technique's potential for broad use in materials research.
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