Abstract
Commercially available unalloyed molybdenum (Low Carbon Arc Cast (LCAC)), Oxide Dispersion Strengthened (ODS) molybdenum, and TZM molybdenum were subject to fracture toughness testing following neutron irradiation at temperatures of nominally 244 C, 407 C, and 509 C to neutron fluences between 1.0 and 4.6 × 1025 n/m2 (E > 0.1 MeV). All alloys exhibited a Ductile to Brittle Transition Temperature that was defined to occur at 30 ± 4 MPa m. The highest post-irradiated fracture toughness values (26-107 MPa m) and lowest DBTT (100-150 C) was observed for ODS molybdenum in the longitudinal orientation. The results for ODS molybdenum are anisotropic with lower post-irradiated toughness values (20-30 MPa m) and higher DBTT (450-600 C) in the transverse (T-L) orientation. The results for ODS molybdenum are better than those for LCAC molybdenum (21-71 MPa m and 450-800 C DBTT). The fracture toughness values measured for LCAC and T-L ODS molybdenum at temperatures below the DBTT were determined to be 8-18 MPa m. The role of microstructure and grain size on post-irradiated fracture toughness was evaluated.
Original language | English |
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Pages (from-to) | 382-413 |
Number of pages | 32 |
Journal | Journal of Nuclear Materials |
Volume | 440 |
Issue number | 1-3 |
DOIs | |
State | Published - 2013 |
Funding
This work was supported under USDOE Contract No. DE-AC11-98PN38206. The following ORNL personnel contributed to this work by specimen preparation and testing (M.M. Lee, J.P. Strizak, A.W. Williams, and J.L. Bailey). The authors acknowledge D. Ward at Bettis for void size/number analysis and R.W. Smith and J.E. Hack for numerous discussions on this work. Research supported in part by ORNL’s Shared Research Equipment (ShaRE) User Facility, which is sponsored by the Office of Basic Energy Sciences, U.S. Department of Energy.