Project/Area Number |
21760090
|
Research Category |
Grant-in-Aid for Young Scientists (B)
|
Allocation Type | Single-year Grants |
Research Field |
Materials/Mechanics of materials
|
Research Institution | Japan Atomic Energy Agency |
Principal Investigator |
TSURU Tomohito Japan Atomic Energy Agency, 原子力基礎工学研究部門, 研究員 (80455295)
|
Project Period (FY) |
2009 – 2010
|
Project Status |
Completed (Fiscal Year 2010)
|
Budget Amount *help |
¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2010: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2009: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
|
Keywords | 材料設計 / プロセス / 物性 / 評価 / 粒界偏析 / 不純物クラスター / Bragg-Williams近似 / 不純物拡散 / 状態遷移解析 / 粒界拡散 |
Research Abstract |
The segregation of impurities were investigated by Bragg-Williams approximation combined with first principle density functional theory calculations. The segregation tendencies of various elements observed in reactor pressure vessels were considered and the interaction characteristics between □-Fe and each impurity element were estimated by mean field approximation. Stable N-atom impurity clusters were subsequently chosen to evaluate the changes in free energy for clustering. These calculations show that Cu and Mn impurities embedded in □-Fe are more stable when they are in the segregated state. Conversely, Nb and Ta are stable in the separately solute state. The present estimates provide reliable suggestions for the segregation characteristics.
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