Observation of Grain Growth in 3D Robert M. Suter,Carnegie Mellon University, DMR 0805100

1. Observation of Grain Growth in 3DRobert M. Suter,Carnegie Mellon University, DMR 0805100 (b) (a) Most materials are made up of small crystalline grains and materials properties (strength, corrosion resistance, etc) depend on grain size and the spatial distribution of grain orientations. These polycrystalline materials are used in essentially all sectors of our economy; learning to optimize properties has huge potential economic, energy, and environmental impact. Using the high energy x-rays available at the Advanced Photon Source, we have developed a method of non-destructively determining grain orientations, locations, and shapes. We recently have made one of the first ever observations of grain growth in three dimensions. A volume of high purity aluminum was measured, then heated and re-measured. The images at the right demonstrate that subtle growth was observed. This growth will be compared to theories based on a variety of growth driving forces. (a) A 2d slice of aluminum showing grains as different colors. Black lines are grain boundaries. (b) The area swept out by boundary motion is shown in shades of red. (c) A 3d rendering of the sample after annealing. Colors are the same as in (a); lines show the boundary planes. (d) A 3d version of (b) with coloring by the rotation between grains. (c) (d)

2. Observation of Grain Growth in 3DRobert M. Suter, Carnegie Mellon University, DMR 0805100 • Project Impacts • Facility development at APS 1-ID: The project uses and helps develop a unique experimental facility for studies of individual grains in polycrystals. We are a part of a collaboration aimed at making this into a general user facility for the materials and engineering communities. Approval by APS management was announced to build a new dedicated end station for this facility. • One Physics graduate student is fully supported by the project. Four others, with separate funding, interact with the project. • Two undergraduate students were supported over the summer of 2009 by an REU supplement. Four students are involved during the academic year, two of whom are women. These students are Physics, Electrical and Computer Engineering, and Computer Science majors. • The project is publicized at conferences and workshops and two publications are in preparation. Beamline 1-ID at the Advanced Photon Source. This is a unique high energy beam line with refractive focusing optics (left) and a high precision sample stage (right). Detectors and other hardware are continuing to be developed. Graduate and undergraduate students are trained at CMU on a general purpose laboratory x-ray system (right).