Equation of state and phase evolution of U-7.7Nb with implications for the understanding of dynamic behavior of U-Nb alloys
Here, we performed in-situ high P-T neutron diffraction experiments on U-7.7Nb. Our results show that the tetragonal γo phase is substantially more compressible than the monoclinic α" phase. As the pressure increases, this leads to increased volume collapse and stress relaxation for the reverse martensitic transformation, α" → γ°. At moderately elevated temperatures, a substantial strain-induced stabilization against transformation into a body centered cubic γ phase was observed in the γ° phase. Additionally, it was discovered that the ability to retain the metastable γ phase, formed from rapid heating of thermally reset γ°, has subtle dependence on the austenitization temperature. The present findings provide a direct test for the hypotheses proposed to explain the low-pressure shock behaviors of the U-Nb alloys.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1544740
- Report Number(s):
- LA-UR-19-22127
- Journal Information:
- Applied Physics Letters, Vol. 114, Issue 22; ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Similar Records
Mechanisms of ultrafine-grained austenite formation under different isochronal conditions in a cold-rolled metastable stainless steel
Recent observations of phase transformations in a U--Nb--Zr alloy