The Potential Link Between High Angle Grain Boundary Morphology and Grain Boundary Deformation in a Nickel-Based Superalloy (Postprint)
Interim rept. 23 Jul 2013-12 May 2015
AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
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Focused ion beam FIB based serial sectioning was utilized to characterize the morphology of two high angle grain boundaries HAGB in a nickel based superalloy, one that experienced grain boundary sliding GBS and the other experienced strain accumulation, during elevated temperature constant stress loading conditions. A custom script was utilized to serial section and collection-induced secondary electron images from the FIB-SEM system. The MATLAB based MIPARTM software was utilized to align, segment and reconstruct 3D volumes from the sectioned images. Analysis of the 3D data indicates that the HAGB that exhibited GBS had microscale curvature that was planar in nature, and local serrations on the order of 150nm. In contrast, the HAGB that exhibited strain accumulation was not planar and had local serrations an order of magnitude greater than the other grain boundary. It is hypothesized that the serrations and the local grain boundary network are key factors in determining which grain boundaries experience GBS during creep deformation.
- Properties of Metals and Alloys
- Computer Programming and Software