大型放射光施設 SPring-8

日　時 : 2010年9月28日 (火)　 14 : 00-15 : 00

場　所 : 上坪講堂

Speaker : Robert M. Suter

Language : English

Affiliate : Department of Physics and Materials Science and Engineering, Carnegie Mellon University

Title : Non-destructive Mapping of Bulk Microstructures using High Energy X-ray Diffraction Microscopy

Abstract :
High energy (> 50keV) x-rays penetrate through millimeter sized samples and thus offer the opportunity to probe bulk structures and their responses to processing treatments. The 1-ID beamline at the Advanced Photon Source is a dedicated facility for high energy x-ray scattering offering a high energy undulator, focusing optics, a variety of two dimensional detectors and multiple sample environments. High Energy X-ray Diffraction Microscopy (HEDM) measurements focus on obtaining single crystal-like information from individual grains within bulk, polycrystalline ensembles. This talk will report primarily on near-field orientation mapping measurements but will also briefly illustrate some of the far-field capabilities at the beamline.

HEDM microstructure mapping measurements use a line focused x-ray beam to illuminate a quasi-planar cross-section of sample. Details of data collection protocols and our real-space microstructure reconstruction method will be presented. By collecting a sequence of planar sections we build three dimensional digital representations of microstructure similar to those obtained by 3D electron backscatter diffraction measurements. Because the HEDM measurement is non-destructive, we can track microstructural responses to thermal and mechanical treatments. These measurements are an ideal way to test and validate analytic and computational models of materials response. Measurements on a variety of elemental metals will illustrate experimental resolution in orientation and real space and the extent of development of analysis tools.

With a large far-field detector, strain states of individual grains become accessible. Work on a β-Ti alloy sample illustrates a close interplay between computational modeling of plastic response and direct measurements. Finally, the prospect of combining near- and far-field measurements to obtain full three dimensional maps of both crystallographic orientation and strain will be discussed.

担当者 : 上杉　健太朗
PHS : 3928
uesugi@spring8.or.jp