Dose dependence of strength after low-temperature irradiation in metallic materials

Journal Article · Tue Jan 01 00:00:00 EST 2013 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-012-1309-z· OSTI ID:1061535

Byun, Thak Sang ^[1]; Li, Meimei ^[2]; Farrell, Kenneth ^[1]

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1. ORNL
2. Argonne National Laboratory (ANL)

This study intends to review and characterize the low-temperature (< 200 oC) irradiation hardening behaviors in metallic materials and to propose new interpretations on the dose dependence of strength, particularly in the pre-hardening and saturation regimes. The analysis results of yield stress-dose curves indicate that four dose-dependence regimes exist: the pre-hardening, main hardening, saturation, and embrittlement regimes. The semi-log plots of yield stress versus dose data revealed that the pre-hardening regime displaying zero-hardening or softening was common at least for the alloys with low dose data available. It was observed that the dose range of the pre-hardening regime increased with the strength of material, which indicates that slower initiation in irradiation hardening is expected when strength is higher. For the majority of the metallic materials analyzed, it was reconfirmed that the exponent of the power-law hardening function was evaluated to be about 0.5 in the main hardening regime and about 0.1 in the saturation regime. In these positive hardening regimes the low strength pure metals such as Fe, Ta, Cu, and Zr displayed lower hardening exponents. The minimum dose to the saturation of irradiation hardening was in the range of 0.003 0.08 dpa, depending on the category of materials. It was also reaffirmed that there exists a strong relationship between the saturation in irradiation hardening and the occurrence of plastic instability at yield.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1061535
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Vol. 44, Issue 1; ISSN 1073-5623
• Publisher: ASM International
• Country of Publication: United States
• Language: English