skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Tensile and Fracture Toughness Properties of Neutron-Irradiated CuCrZr

Abstract

Tensile and fracture toughness properties of a precipitation-hardened CuCrZr alloy were investigated in two heat treatment conditions: solutionized, water quenched and aged (CuCrZr SAA), and hot isostatic pressed, solutionized, slow-cooled and aged (CuCrZr SCA). The second heat treatment simulated the manufacturing cycle for large components, and is directly relevant for the ITER divertor components. Specimens were neutron irradiated at {approx}80 C to two fluences, 2 x 10{sup 24} and 2 x 10{sup 25} n/m{sup 2} (E > 0.1 MeV), corresponding to displacement doses of 0.15 and 1.5 displacements per atom (dpa). Tensile and fracture toughness tests were carried out at room temperature. Significant irradiation hardening and plastic instability at yield occurred in both heat treatment conditions with a saturation dose of {approx}0.1 dpa. Neutron irradiation slightly reduced fracture toughness in CuCrZr SAA and CuCrZr SCA. The fracture toughness of CuCrZr remained high up to 1.5 dpa (J{sub Q} > 200 kJ/m{sup 2}) for both heat treatment conditions.

Authors:
 [1];  [1];  [2]
  1. ORNL
  2. Argonne National Laboratory (ANL)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); High Flux Isotope Reactor
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
979117
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Nuclear Materials; Journal Volume: 393; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ALLOYS; ATOMS; DIVERTORS; FRACTURE PROPERTIES; HARDENING; HEAT TREATMENTS; INSTABILITY; IRRADIATION; MANUFACTURING; NEUTRONS; PLASTICS; SATURATION; WATER

Citation Formats

Sokolov, Mikhail A, Zinkle, Steven J, and Li, Meimei. Tensile and Fracture Toughness Properties of Neutron-Irradiated CuCrZr. United States: N. p., 2009. Web.
Sokolov, Mikhail A, Zinkle, Steven J, & Li, Meimei. Tensile and Fracture Toughness Properties of Neutron-Irradiated CuCrZr. United States.
Sokolov, Mikhail A, Zinkle, Steven J, and Li, Meimei. 2009. "Tensile and Fracture Toughness Properties of Neutron-Irradiated CuCrZr". United States. doi:.
@article{osti_979117,
title = {Tensile and Fracture Toughness Properties of Neutron-Irradiated CuCrZr},
author = {Sokolov, Mikhail A and Zinkle, Steven J and Li, Meimei},
abstractNote = {Tensile and fracture toughness properties of a precipitation-hardened CuCrZr alloy were investigated in two heat treatment conditions: solutionized, water quenched and aged (CuCrZr SAA), and hot isostatic pressed, solutionized, slow-cooled and aged (CuCrZr SCA). The second heat treatment simulated the manufacturing cycle for large components, and is directly relevant for the ITER divertor components. Specimens were neutron irradiated at {approx}80 C to two fluences, 2 x 10{sup 24} and 2 x 10{sup 25} n/m{sup 2} (E > 0.1 MeV), corresponding to displacement doses of 0.15 and 1.5 displacements per atom (dpa). Tensile and fracture toughness tests were carried out at room temperature. Significant irradiation hardening and plastic instability at yield occurred in both heat treatment conditions with a saturation dose of {approx}0.1 dpa. Neutron irradiation slightly reduced fracture toughness in CuCrZr SAA and CuCrZr SCA. The fracture toughness of CuCrZr remained high up to 1.5 dpa (J{sub Q} > 200 kJ/m{sup 2}) for both heat treatment conditions.},
doi = {},
journal = {Journal of Nuclear Materials},
number = 1,
volume = 393,
place = {United States},
year = 2009,
month = 1
}
  • Commercial 316L and 316LN alloys have been evaluated for service as the conduit material for the 45-T Hybrid Magnet. The 4 K tensile and fracture toughness properties of these alloys have been measured before and after a simulated Nb{sub 3}Sn reaction heat treatment. The tensile properties have been found to be unaffected by the heat treatment short, low temperature proposed for high performance superconductors. The fracture toughness also does not change with heat treatment although there is evidence of discontinuous intergranular precipitation in the high carbon 316LN alloy. Uncharacteristically low toughness is reported for one alloy in both the asmore » received and heat treated condition.« less
  • A {gamma}-base TiAl alloy with duplex microstructure of lamellar colonies and equiaxed {gamma} grains was prepared with a reactive sintering method. Tensile tests and fracture toughness tests at loading velocities up to 12 m/s (strain rate for tensile tests up to 3.2 {times} 10{sup 2}/s) were carried out. The microstructure of the alloy before and after tensile deformation was carefully examined with a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The fractography of the tensile specimens and fracture toughness specimens was studied. The experimental results demonstrated that the ultimate tensile strength (UTS) and yield strength (YS) increasemore » with increasing strain rate up to 10/s and subsequently level off. The UTS and YS exhibited similar strain rate sensitivity. The strain rate sensitivity exponent at strain rates lower than 10/s is about 1.5 {times} 10{sup {minus}2} and at higher strain rates is almost zero. In this study, fracture toughness was found to be less sensitive to the loading velocity, having values of around 25 MPa {radical}m, which is believed to be attributed to the high strain rate experienced at the crack tip. The predominant deformation mechanism for the strain rates used in this study was found to be twinning. However, in the low strain rate range, the dislocation motion mechanism was operative at the initial deformation stage and twinning dominated the later stage of the deformation process. In the high strain rate range, the entire deformation process was dominated by twinning. The interaction between deformation twinning and grain boundaries resulted in intergranular fracture in the {gamma} grains and delamination of {alpha}{sub 2}/{gamma} interfaces in the lamellar colonies.« less
  • The formation of ‘cleared’ channels in neutron irradiated metals and alloys have been frequently reported for more than 40 years. So far, however, no unambiguous and conclusive evidence showing as to how and where these channels are initiated has emerged. In the following we present experimental results illustrating initiation and propagation of channels during post-irradiation deformation of neutron irradiated copper and a copper alloy. The observations strongly suggest that the channels are initiated at boundaries, large inclusions and even at previously formed cleared channels. Some of the channels have been observed to penetrate through both the twin boundaries and grainmore » boundaries. It is argued that the high stress level reached during post-irradiation tensile tests activate dislocation sources at the sites of stress concentrations at boundaries and interfaces. The propagation of these newly generated dislocations in the matrix causes the formation of cleared channels. Implications of these results are discussed with specific reference to the origin and consequences of plastic flow localization.« less
  • The temperature dependence of fracture toughness in HT9 steel irradiated to high doses was investigated using miniature three-point bend (TPB) fracture specimens. These specimens were from the ACO-3 fuel duct wall of the Fast Flux Test Facility (FFTF), in which irradiation doses were in the range of 3.2 144.8 dpa and irradiation temperatures in the range of 380.4 502.6 oC. A miniature specimen reuse technique has been established for this investigation: the specimens used were the tested halves of miniature Charpy impact specimens (~13 3 4 mm) with diamond-saw cut in the middle. The fatigue precracking for specimens and fracturemore » resistance (J-R) tests were carried out in a MTS servo-hydraulic testing machine with a vacuum furnace following the standard procedure described in the ASTM Standard E 1820-09. For each of five irradiated and one archive conditions, 7 to 9 J-R tests were performed at selected temperatures ranging from 22 C to 600 C. The fracture toughness of the irradiated HT9 steel was strongly dependent on irradiation temperatures rather than irradiation dose. When the irradiation temperature was below about 430 C, the fracture toughness of irradiated HT9 increased with test temperature, reached an upper shelf of 180 200 MPa m at 350 450 C and then decreased with test temperature. When the irradiation temperature 430 C, the fracture toughness was nearly unchanged until about 450 C and decreased with test temperature in higher temperature range. Similar test temperature dependence was observed for the archive material although the highest toughness values are lower after irradiation. Ductile stable crack growth occurred except for a few cases where both the irradiation temperature and test temperature are relatively low.« less