Affiliation: | 1.Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA ;2.Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA ;3.Department of Physics, Carnegie Mellon University, Pittsburgh, PA, 15213, USA ;4.X-ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA ;5.Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA ; |
Abstract: | We use high-energy X-ray diffraction microscopy (HEDM) to characterize the microstructure of Ni-base alloy 725. HEDM is a non-destructive technique capable of providing three-dimensional reconstructions of grain shapes and orientations in polycrystals. The present analysis yields the grain size distribution in alloy 725 as well as the grain boundary character distribution (GBCD) as a function of lattice misorientation and boundary plane normal orientation. We find that the GBCD of Ni-base alloy 725 is similar to that previously determined in pure Ni and other fcc-base metals. We find an elevated density of Σ9 and Σ3 grain boundaries. We also observe a preponderance of grain boundaries along low-index planes, with those along (1 1 1) planes being the most common, even after Σ3 twins have been excluded from the analysis. |