X-ray Vision for Materials
R.M. Suter /CMU MRSEC, Carnegie Mellon University, NSF DMR- 0520425

Researchers in the CMU MRSEC, together with scientists at the advanced photon source, have developed a non-destructive method to visualize the arrangement and orientation of individual crystals within a solid material. High energy X-rays from a synchrotron light source penetrate the material and interact with the crystals in their path. The pattern of transmitted X-rays that emerges from the material is then analyzed by custom software to determine the internal structure of the material. Because the complete X-ray/crystal interaction is modeled, this technique yields far more data than is contained in conventional radiograms. This new tool allows scientists to see within opaque materials with unprecedented detail and, therefore, allows the visualization of a wide range of previously hidden processes, such as crack formation in structural materials.

The figure shows a two-dimensional slice of the microstructure inside of an aluminum
wire, 1 mm in diameter (the blue circle). Each color corresponds to a different crystal
orientation.

This research was conducted by: R.M. Suter,a C. Xiao,a D. Hennessy,a and U. Lienertb
aCarnegie Mellon, Department of Physics and bAdvanced Photon Source

To learn more, see http://www.andrew.cmu.edu/user/suter/3dxdm/3dxdm.html

Past Nuggets

• International Collaboration on Grain Boundary Engineered Materials (Research Partnership Nugget: 06/06)
• High School Teacher Gains Recognition For Work with the CMU MRSEC (Education Nugget: 06/06)
• Growing Thin Films with Only One Hand (Research Nugget, 3/05)
• Large Scale, Anisotropic Grain Growth Simulations (Research Partnership Nugget: 03/05)
• Predictability and Control in Polycrystalline Structure (Research Nugget: 11/04)
• Polycrystals Have Good Habits (Research Nugget: 6/04)
• Do You Really Need Titanium Golf Clubs? (Education Nugget: 8/04)
• What should the three little pigs really have used? (Education Nugget: 8/04)
• Synchronized Transatlantic Synchrotron Research (International collaboration nugget: 11/03)
• Powering Future Engines (Education Nugget: 8/03)
• 5-D Vision (Research Nugget: 1/03)
• Measurement of Relative Grain Boundary energies (Research Nugget: 3/02)
• Discovery of Texture in the Space of Grain Boundary Planes (Research Nugget: 1/01)
• Experimental Determination of Relative Grain Boundary Mobilities in Al Alloys (Research Nugget: 1/00)

Movies illustrating Results

• Watch a movie illustrating illustrating five-dimensional grain boundary character distribution results. As the movie runs, the 2D plots illustrate the distribution of grain boundary planes at different points in the 3D misorientation space. The current point in the 3D space is illustrated in the lower right and the current bicrystal configuration is illustrated in the lower left. In the upper portion, data recorded by traditional means (left) and recovered from the new statistical procedure (right) are compared. All illustrations are for [100] type misorientations in SrTiO₃.
• Habit data for WC crystals. As the movie progresses, more and more observations from planar sections are added to the distribution, until the peaks at the basal and prismatic positions become relatively constant.
• Watch a movie illustrating the distribution of planes for MgO grain boundaries with misorientations about <110>. In this movie, the distribution of planes is plotted as the angle of misorientation about <110> increases from 5 to 60 degrees during the progress of the clip.
• Two dimensional grain growth simulation by David Kinderlehrer
• Watch a simulation of grain growth