NSUF 20-4180: In situ dual beam radiation on additively manufactured Haynes 230 Ni alloys with precipitates New Proposal
The main objective of this proposal is to use in situ dual beam radiation technique (at IVEM-Argonne National Lab) to investigate irradiation induced microstructure evolution in additively manufactured (AM) Haynes 230 alloys. The results will provide guidance for tailoring the microstructure of high strength Ni-based alloys fabricated by direct laser melt sintering to enhance the swelling resistance and high temperature radiation stability of Ni alloys under reactor operation conditions. He atom generated by nuclear transmutation is one of the major issues to the mechanical reliability of reactor structural materials. Two strategies have been widely applied to delay “bubble-to-void” transition which could cause unbounded cavity growth. One is to maximize the critical bubble diameter beyond which bubbles transform into voids. The other is to maximize the number density of stable He bubbles. Defect sinks, such as grain boundaries (GBs) and phase boundaries, have demonstrated their capability to effectively store He to form fine He bubbles and alleviate void swelling. In this study, Haynes 230 alloys fabricated by direct metal laser sintering contain well aligned arrays of M6C nanoprecipitates along the dislocation cell walls. The alignment of precipitates along certain crystallographic direction may lead to orientation dependent defect-interface interactions and defect distributions and impact the overall sink strength. Furthermore, the dislocation cell walls in conjunction with nanoprecipitates form the dislocation-precipitate network. The nanoprecipitates can manage He. The dislocation cells are diffusion channels to transmit point defects to precipitates, which may accelerate defect recombination and affect the vacancy supersaturation and void swelling rate. In situ dual-beam (Kr + He ions) radiation will be performed at Argonne National Lab at various temperatures ranging from 350 to 700 °C at different He-to-dpa ratios (10, 100, 1000 ppm/dpa) to deliver a comprehensive understanding on the He management capacity and radiation stability of AM Ni alloys. The influence of fine precipitates on radiation response of AM Ni alloys will be studied by tilting the TEM samples to various zone axes (such as and ) and the results will be compared with the wrought Haynes 230 Ni alloy. Post-radiation TEM analysis will be carried out at Purdue.
Additional Info
| Field | Value |
|---|---|
| Abstract | The main objective of this proposal is to use in situ dual beam radiation technique (at IVEM-Argonne National Lab) to investigate irradiation induced microstructure evolution in additively manufactured (AM) Haynes 230 alloys. The results will provide guidance for tailoring the microstructure of high strength Ni-based alloys fabricated by direct laser melt sintering to enhance the swelling resistance and high temperature radiation stability of Ni alloys under reactor operation conditions. He atom generated by nuclear transmutation is one of the major issues to the mechanical reliability of reactor structural materials. Two strategies have been widely applied to delay “bubble-to-void” transition which could cause unbounded cavity growth. One is to maximize the critical bubble diameter beyond which bubbles transform into voids. The other is to maximize the number density of stable He bubbles. Defect sinks, such as grain boundaries (GBs) and phase boundaries, have demonstrated their capability to effectively store He to form fine He bubbles and alleviate void swelling. In this study, Haynes 230 alloys fabricated by direct metal laser sintering contain well aligned arrays of M6C nanoprecipitates along the dislocation cell walls. The alignment of precipitates along certain crystallographic direction may lead to orientation dependent defect-interface interactions and defect distributions and impact the overall sink strength. Furthermore, the dislocation cell walls in conjunction with nanoprecipitates form the dislocation-precipitate network. The nanoprecipitates can manage He. The dislocation cells are diffusion channels to transmit point defects to precipitates, which may accelerate defect recombination and affect the vacancy supersaturation and void swelling rate. In situ dual-beam (Kr + He ions) radiation will be performed at Argonne National Lab at various temperatures ranging from 350 to 700 °C at different He-to-dpa ratios (10, 100, 1000 ppm/dpa) to deliver a comprehensive understanding on the He management capacity and radiation stability of AM Ni alloys. The influence of fine precipitates on radiation response of AM Ni alloys will be studied by tilting the TEM samples to various zone axes (such as <110> and <001>) and the results will be compared with the wrought Haynes 230 Ni alloy. Post-radiation TEM analysis will be carried out at Purdue. |
| Award Announced Date | 2020-07-14T14:13:28.31 |
| Awarded Institution | Idaho National Laboratory |
| Facility | Advanced Test Reactor |
| Facility Tech Lead | Alina Zackrone, Wei-Ying Chen |
| Irradiation Facility | Intermediate Voltage Electron Microscopy (IVEM)-Tandem Facility |
| PI | Xinghang Zhang |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 4180 |