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Title: Temperature dependence of the radiation damage microstructure in V-4Cr-4Ti neutron irradiated to low dose

Technical Report ·
DOI:https://doi.org/10.2172/335372· OSTI ID:335372
;  [1]
  1. Oak Ridge National Lab., IL (United States)

Transmission electron microscopy (TEM) was performed on the US program heat of V-4Cr-4Ti (heat No. 83665) irradiated to damage levels of 0.1--0.5 displacements per atom (dpa) at 110--505 C in the High Flux Beam Reactor at Brookhaven. A high density ({approximately}1 {times} 10{sup 23}/m{sup 3}) of small ({approximately}3.0 nm diameter) faulted dislocation loops were observed at irradiation temperatures blow 275 C. These dislocation loops became unfaulted at temperatures above {approximately}275 C, and a high density of small Ti-rich defect clusters lying on {l_brace}001{r_brace} planes appeared along with the unfaulted loops at temperatures above 300 C. The density of the {l_brace}001{r_brace} defect clusters was much higher than that of the dislocation loops at all temperatures above {approximately}300 C. The density of both types of defects decreased with increasing temperature above 300 C, with the most rapid decrease occurring for temperatures above 400 C. Based on the TEM and tensile measurements, the dislocation barrier strengths of the faulted dislocation loops and {l_brace}001{r_brace} defect clusters are {approximately}0.4--0.5 and 0.25, respectively. This indicates that both types of defects can be easily sheared by dislocations during deformation. Cleared dislocation channels were observed following tensile deformation in a specimen irradiated at 268 C.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
OSTI ID:
335372
Report Number(s):
DOE/ER-0313/23; ON: DE98004697; TRN: 99:005162
Resource Relation:
Other Information: PBD: Mar 1998; Related Information: Is Part Of Fusion materials semiannual progress report for the period ending December 31, 1997; Burn, G. [ed.] [comp.]; PB: 390 p.
Country of Publication:
United States
Language:
English