NSUF 18-1146: Micro-mechanical characterization of long range order in Ni-Cr alloys and their response to radiation damage
Separate effects testing will be performed on unaged, thermally aged and irradiated Ni-30wt.% Cr model alloy specimens to quantify mechanical degradation as a function of long range order (LRO) phase transformations. Samples are as received, aged (10, 100 and 1000 hours) at 475°C or irradiated with 2 MeV protons at 300°C to 1.5 or 6 dpa at a dose rate of 10-5 dpa/sec. All samples are currently ready for micro-mechanical testing and will be performed the first half of 2018. The as received samples are expected to have no LRO precipitates in the material while the aged/irradiated material will have progressively increasing fractions of LRO features present orientated along specific crystallographic planes. Therefore, it is expected that the aged material will experience higher yield strengths and lower ductility. Proton irradiation has been shown to accelerate the ordering transformation, however, the secondary hardening effects caused by radiation-induced defects has not been characterized. Hardness (measured with nanoindentation) and yield strength (measured with micro-pillar compression testing) will be used to compare the aged to the irradiated samples to quantify the acceleration of ordering rate with irradiation and the contribution to hardening due to radiation damage. We will also study the role of grain orientation on the mechanical strength of each condition and follow the failure of pillars in-situ to understand the effects of localized failure as it is described in [A. Reichardt et al. JNM 2017]. We believe that a thorough energy balance analysis on pillars will provide us with detailed information on aging and irradiation effects in light water reactor relevant materials such as alloys 690 and 625.
Additional Info
| Field | Value |
|---|---|
| Abstract | Separate effects testing will be performed on unaged, thermally aged and irradiated Ni-30wt.% Cr model alloy specimens to quantify mechanical degradation as a function of long range order (LRO) phase transformations. Samples are as received, aged (10, 100 and 1000 hours) at 475°C or irradiated with 2 MeV protons at 300°C to 1.5 or 6 dpa at a dose rate of 10-5 dpa/sec. All samples are currently ready for micro-mechanical testing and will be performed the first half of 2018. The as received samples are expected to have no LRO precipitates in the material while the aged/irradiated material will have progressively increasing fractions of LRO features present orientated along specific crystallographic planes. Therefore, it is expected that the aged material will experience higher yield strengths and lower ductility. Proton irradiation has been shown to accelerate the ordering transformation, however, the secondary hardening effects caused by radiation-induced defects has not been characterized. Hardness (measured with nanoindentation) and yield strength (measured with micro-pillar compression testing) will be used to compare the aged to the irradiated samples to quantify the acceleration of ordering rate with irradiation and the contribution to hardening due to radiation damage. We will also study the role of grain orientation on the mechanical strength of each condition and follow the failure of pillars in-situ to understand the effects of localized failure as it is described in [A. Reichardt et al. JNM 2017]. We believe that a thorough energy balance analysis on pillars will provide us with detailed information on aging and irradiation effects in light water reactor relevant materials such as alloys 690 and 625. |
| Award Announced Date | 2018-02-01T14:10:46.367 |
| Awarded Institution | Center for Advanced Energy Studies |
| Facility | Microscopy and Characterization Suite |
| Facility Tech Lead | Alina Zackrone, Peter Hosemann, Yaqiao Wu |
| Irradiation Facility | None |
| PI | Julie Tucker |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 1146 |