2016 Fiscal Year Annual Research Report
Dynamic fracture toughness of tungsten under ternary loading
| Project/Area Number |
26820397
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| Research Institution | Osaka University |
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Principal Investigator |
Lee Heun Tae 大阪大学, 工学研究科, 助教 (90643297)
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | Tungsten / Laser ultrasonics / Radiation damage / Hydrogen / Mechanical properties / Helium / Fracture toughness |
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| Outline of Annual Research Achievements |
H28 focused on: (1) characterisation of binary loading effect of radiation damage and hydrogen on tungsten mechanical properties and hydrogen transport, (2) the microstructure changes under combined ternary loading (H,He, and radiation damage), (3) characterisation of surface breaking cracks using surface waves and application to W-monoblock, and (4) characterisation of elastic properties of advanced W-fiber reinforced W components with superior fracture toughness.
Experiments related to (1) showed that H and radiation damage effects increase the elastic modulus, while the H implanted at the surface is thermally stable between 100-500 K. Experiments related to (2) showed increased ordering of He bubbles in the presence of radiation damage. Experiments related to (3) showed that the depth of surface breaking cracks can be characterised non-destructively using surface waves using laser ultrasonics, and the results were applied to real W-monoblock. Experiments related to (4) showed that advanced W-fiber reinforced W components have similar elastic properties as bulk W but with superior fracture toughness due to the fibers. These results provide important basic insight into the understanding of W mechanical properties and fracture behavior under hydrogen-helium-radiation damage loading. Part of the works related to (3) and (4) will be presented at international conference PFMC-16 and ICFRM-18 in 2017.
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