Effects of Long-Term Service on The Aging Behavior of A Water-Quenched U{sub 6}Nb Alloy
- Chemistry and Materials Science Directorate, Lawrence Livermore National Laboratory, Livermore, California (United States)
Microhardness testing and transmission electron microscopy are used to study the effects of long-term service on the aging behavior of a water-quenched U{sub 6} wt.% Nb alloy when subjected to isothermal aging at 200 deg. C. The original {alpha}'' phase in the WQ-U{sub 6}Nb alloy is found to become partially ordered over 18 years of aging at ambient temperatures, i.e., natural aging, forming a microstructure that is featured by antiphase domain boundaries (APBs). When subsequently aged at 200 deg. C, an ordered phase U{sub 3}Nb is precipitated through a nucleation-and-growth mechanism, suppressing spinodal decomposition that occurs when the water-quenched alloy is artificially aged at the same temperature. The different phase transformation paths lead to different microhardness changes during artificial aging: the naturally aged alloy is more slowly hardened, but to a greater microhardness peak value. (authors)
- Research Organization:
- Materials Research Society, 506 Keystone Drive, Warrendale, PA, 15086-7573 (United States)
- OSTI ID:
- 21083710
- Resource Relation:
- Conference: Symposium Actinides 2006 - Basic Science, Applications and Technology, Boston, MA (United States), 26-30 Nov 2006; Other Information: Country of input: France; Related Information: In: Proceedings of the symposium Actinides 2006 - Basic Science, Applications and Technology, by Blobaum, Kerri J.M. [ed. CMS, Lawrence Livermore National Laboratory, Livermore, California (United States)]; Chandler, Elaine A. [ed. Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)]; Havela, Ladislav [ed. Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic)]; Maple, M. Brian [ed. University of California, San Diego, La Jolla, California (United States)]; Neu, Mary P. [ed. Los Alamos National Laboratory, Los Alamos NM (United States)], v. 986, 209 pages.
- Country of Publication:
- United States
- Language:
- English
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