Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1573053 | Materials Science and Engineering: A | 2016 | 12 Pages |
Abstract
A new larger heat of a 14YWT nanostructured ferritic alloy (NFA), FCRD NFA-1, was synthesized by ball milling FeO and argon atomized Fe-14Cr-3W-0.4Ti-0.2Y (wt%) powders, followed by hot extrusion, annealing and cross rolling to produce an â10 mm-thick plate. NFA-1 contains a bimodal size distribution of pancake-shaped, mostly very fine scale, grains. The as-processed plate also contains a large population of microcracks running parallel to its broad surfaces. The small grains and large concentration of Y-Ti-O nano-oxides (NOs) result in high strength up to 800 °C. The uniform and total elongations range from â1-8%, and â10-24%, respectively. The strength decreases more rapidly above â400 °C and deformation transitions to largely viscoplastic creep by â600 °C. While the local fracture mechanism is generally ductile-dimple microvoid nucleation, growth and coalescence, perhaps the most notable feature of tensile deformation behavior of NFA-1 is the occurrence of periodic delamination, manifested as fissures on the fracture surfaces.
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Authors
M.E. Alam, S. Pal, K. Fields, S.A. Maloy, D.T. Hoelzer, G.R. Odette,