Beanspruchungscharakteristik des Materialübergangs von Divertorverbundkomponenten für thermonukleare Reaktoren unter fusionsrelevanten Belastungen
Beanspruchungscharakteristik des Materialübergangs von Divertorverbundkomponenten für thermonukleare Reaktoren unter fusionsrelevanten Belastungen
A duplex divertor component composed of dissimilar materials experiences considerable thermal stresses under fusion operating load conditions due to the mismatch of the thermomechanical properties. Thermal stresses in the interface of a CFC/TZM bond joint for divertor applications are analyzed using...
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Personal Name(s): | You, J. H. (Corresponding author) |
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Breitbach, G. / Linke, Jochen / Nickel, Hubertus | |
Contributing Institute: |
Publikationen vor 2000; PRE-2000; Retrocat |
Imprint: |
Jülich
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag
1996
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Physical Description: |
127 p. |
Document Type: |
Report Book |
Research Program: |
ohne Topic |
Series Title: |
Berichte des Forschungszentrums Jülich
3286 |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
A duplex divertor component composed of dissimilar materials experiences considerable thermal stresses under fusion operating load conditions due to the mismatch of the thermomechanical properties. Thermal stresses in the interface of a CFC/TZM bond joint for divertor applications are analyzed using the finite element method. A typical fusion operation condition is simulated by applying a pulsed high heat flux loading. The stress states near the free surface edge of the bond interface are very critical because the stress intensification occurs which shows sometimes singularities. A semi analytical procedure is employed to describe the stress singularity in terms of the stress intensity factor by the fracture mechanical analogy. The effect of the transient temperature gradient on the stress singularity and the interfacial stress is investigated quantitatively. Stress singularities at the tip of the interfacial cracks are characterized quantitatively applying the crack flank displacement analysis. The evolution of the stress intensity factors and the strain energy release rates during a typical high heat flux load are determined. The difference in the thermal load characteristics between the edge crack and the center crack is discussed. Elasto-plastic analysis is performed on a CFC/Cu/TZM bond joint under thermal loads. The effect of the ductile interlayer on the interfacial stress is analyzed. Thermomechanical fatigue response of the braze and the interfaces under cyclic thermal loads is investigated. High heat flux simulation tests are conducted on a brazed CFC/Cu/TZM divertor element in an electron beam test facility. Microstructures of the damaged interfaces and the deformed copper braze tested under different power densities are investigated. Thermomechanical damage characteristics of the bond interface under fusion relevant load conditions and possible failure mechanisms are discussed. Various plastic flow morphologies in the braze layer and the corresponding slip mechanisms are investigated. Actively cooled divertor mock-ups consisting of different low-Z armor tiles brazed to TZM heat sinks are tested in an electron beam test facility. Screening and thermal fatigue tests were perfomed on the mock-ups to estimate the overall thermomechanical performance of various material combinations. Microstructures were investigated to elucidate the degradation of the joints. Thermal stress analysis is carried out for the simulation tests. The cyclic behavior of the thermal stresses is characterized. |