NSUF 16-610: Critical evaluation of radiation-induced segregation in Nickle base alloys subjected to proton irradiation
We propose to investigate the radiation-induced segregation (RIS) in several commercialized nickel base alloys subjected to 4-5 dpa proton irradiations. RIS experiments can be performed using transmission electron microscopy (TEM) with a large tilt range holder and an accurate EDX system. The ion irradiations were completed at the Michigan Ion Beam Laboratory (MIBL) at the University of Michigan using well controlled irradiation conditions such as, temperature (360 ±5°C) and pressure (below 5×10-8 torr). These nickel base alloys include alloy 625, alloy 718, and alloy 725, all of which have potential application for the structural components of light water reactors. Alloy 625 was given different heat treatments and are denoted as alloy 625 (solid solution and water quenching), 625Plus (solid solution and fan cool, and then ageing). The broader goal of our project is to identify a radiation resistant material from a wide range of commercial alloys. Radiation induced segregation (RIS) is used as one of the indicators of the radiation resistance of materials for its potential impacts on irradiation assisted stress corrosion cracking (IASCC). In this regard, we will examine whether: 1) RIS can be significantly affected by thermal mechanical treatment history in alloy 625, 2) RIS can be significantly affected by alloy elements from a comparison of 625Plus, alloy 718 and alloy 725, and 3) RIS at the precipitate-matrix interface can mirror that of a grain boundary. The logic behind these hypotheses is that the grain boundary and the precipitate matrix interface act as defect sinks. The coupling of defect fluxes and alloying elements fluxes toward and away from defect sinks control RIS. Impact of this work: An understanding of the heat treatment and alloying effects on RIS can be used to design new alloys or new thermal-mechanical treatments of existing alloys with better irradiation tolerance. Period of performance: 2 weeks instrument time. Other related examination and analysis will be conducted at the PI’s home institution.
Additional Info
| Field | Value |
|---|---|
| Abstract | We propose to investigate the radiation-induced segregation (RIS) in several commercialized nickel base alloys subjected to 4-5 dpa proton irradiations. RIS experiments can be performed using transmission electron microscopy (TEM) with a large tilt range holder and an accurate EDX system. The ion irradiations were completed at the Michigan Ion Beam Laboratory (MIBL) at the University of Michigan using well controlled irradiation conditions such as, temperature (360 ±5°C) and pressure (below 5×10-8 torr). These nickel base alloys include alloy 625, alloy 718, and alloy 725, all of which have potential application for the structural components of light water reactors. Alloy 625 was given different heat treatments and are denoted as alloy 625 (solid solution and water quenching), 625Plus (solid solution and fan cool, and then ageing). The broader goal of our project is to identify a radiation resistant material from a wide range of commercial alloys. Radiation induced segregation (RIS) is used as one of the indicators of the radiation resistance of materials for its potential impacts on irradiation assisted stress corrosion cracking (IASCC). In this regard, we will examine whether: 1) RIS can be significantly affected by thermal mechanical treatment history in alloy 625, 2) RIS can be significantly affected by alloy elements from a comparison of 625Plus, alloy 718 and alloy 725, and 3) RIS at the precipitate-matrix interface can mirror that of a grain boundary. The logic behind these hypotheses is that the grain boundary and the precipitate matrix interface act as defect sinks. The coupling of defect fluxes and alloying elements fluxes toward and away from defect sinks control RIS. Impact of this work: An understanding of the heat treatment and alloying effects on RIS can be used to design new alloys or new thermal-mechanical treatments of existing alloys with better irradiation tolerance. Period of performance: 2 weeks instrument time. Other related examination and analysis will be conducted at the PI’s home institution. |
| Award Announced Date | 2015-12-16T00:00:00 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | Kory Linton |
| Irradiation Facility | None |
| PI | Miao Song |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 610 |