Microstructure and Mechanical of U-6Nb and U-8Nb in Gamma Quenched and Long-Term Aged Conditions
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
This report documents the mechanical response and associated microstructure in a number of recent Los Alamos studies of U-6Nb and U-8Nb alloys in the as-quenched and artificially aged conditions, to serve as a primary data reference. Quasi-static tensile and hardness data (in the form of averages) are reported along with microstructures revealed by light optical and scanning electron microscopy. Total elongation data were converted to a common standard for ease of comparison of data from different tensile specimen geometries. A variety of alternate measures of total tensile elongation confirmed the trends one would find from considering only extensometer data. The various U-Nb material pedigrees and experimental conditions are as follows. Y-12-produced U-6Nb as quenched – effect of machining damage as quenched – effect of extensometer length 200oC ages for up to 22 days Rocky Flats-produced U-6Nb 40, 65, and 90oC ages for up to 10 years 300, 350, and 400°C ages for up to 1.2 years Los Alamos-produced nonbanded U-5.6Nb and U-7.7Nb variety of ages over 100-600°C for up to 5 years We characterized the chemical banding by microprobe and Knoop microhardness surveyed over long regions in a dozen Y-12 U-6Nb specimens. As expected, the light-vs.-dark imaging response (both by light optical and scanning electron microscopy) correlated well with the local wt.% Nb. However, the hardness did not correlate well with either imaging or microprobe, and hence cannot be used to predict the local wt.% Nb.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1810412
- Report Number(s):
- LA-14487
- Country of Publication:
- United States
- Language:
- English
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