|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Nanostructured Materials for Nuclear Applications
||On the Nano-Oxide Phase in MA957 and FCDR NFA-1
||Yuan Wu, Stephan Kraemer, soupitak Pal, George Robert Odette, Nathan Bailey, Peter Hosemann, James Ciston
|On-Site Speaker (Planned)
TEM on variants of 14YWT nanostructured ferritic alloys (NFA) are reported: as-extruded, annealed friction stir weld and irradiated MA957; and a recent NFA heat FCDR NFA1. Previous studies found that the nano-oxides (NO) are predominantly Y2Ti2O7 pyrochlore (2-2-7). Extracted NO have been unambiguously identified as 2-2-7 oxides. However, in foil characterization of the smallest < 3 nm NO is challenging. NO have variously been reported to be 2-2-7, Y2TiO5, amorphous and Ti-rich rock salt (Fm-3m) structures; indeed, all may exist. Aberration corrected TEM exit wave analysis and HAADF STEM find 2-2-7 in the friction stir weld, with a cube on edge (100)<110>o//(100)<001>fe orientation relationship and significant strains which vary with size. Phase identification was more difficult in other cases. Here we emphasize the use of extra spots in the power spectra found by FFT in larger areas containing < 3 nm ‘invisible’ NO that are consistent with 2-2-7.
||Planned: A print-only volume