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Polychromatic microdiffraction characterization of defect gradients in severely deformed materials.
Rozaliya I Barabash1, Gene E Ice, Wenjun Liu
1Materials Science and Technology Division of Oak Ridge National Laboratory, Oak Ridge, TN, United States. barabashr@ornl.gov
Micron (Oxford, England : 1993)
|May 13, 2008
Summary
Friction stir welding causes local lattice rotations in titanium. Polychromatic X-ray microdiffraction revealed strain gradients and dislocations, highlighting its use for studying material deformation.
Area of Science:
- Materials Science
- Crystallography
- Mechanical Engineering
Background:
- Severe plastic deformation significantly alters material properties.
- Understanding microstructural changes is crucial for material performance.
- Friction stir welding (FSW) is an advanced joining technique for metals.
Purpose of the Study:
- To analyze local lattice rotations in polycrystalline titanium after friction stir welding.
- To investigate the microstructural evolution and strain distribution in the weld zone.
- To demonstrate the utility of polychromatic X-ray microdiffraction for characterizing deformation.
Main Methods:
- Nondestructive three-dimensional (3D) spatially resolved polychromatic X-ray microdiffraction was employed.
- High-resolution analysis of the local crystal structure was performed.
- Measurements focused on the restructured surface layer and neighboring regions.
Main Results:
- Significant local lattice rotations were observed in the deformed titanium.
- Strong gradients of strain were detected near the surface.
- Geometrically necessary dislocations were identified in the analyzed regions.
Conclusions:
- Polychromatic X-ray microdiffraction is a powerful technique for studying deformation in complex materials.
- The study provides insights into the microstructural effects of friction stir welding on titanium.
- Understanding these effects is vital for optimizing welding processes and material applications.
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