Modeling dislocation evolution in irradiated alloys
| Autor: | R. E. Stoller |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Dislocation creep
geography Void (astronomy) geography.geographical_feature_category Materials science Metallurgy Metals and Alloys Mechanics Condensed Matter Physics Crystallographic defect Sink (geography) Creep Mechanics of Materials medicine Forensic engineering Climb Swelling medicine.symptom Dislocation human activities |
| Zdroj: | Metallurgical Transactions A. 21:1829-1837 |
| ISSN: | 2379-0180 0360-2133 |
| DOI: | 10.1007/bf02647229 |
| Popis: | Neutron irradiation of structural materials leads to such observable changes as creep and void swelling. These effects are due to differential partitioning of point defects. Although most radiationproduced point defects recombine with an antidefect, a very small fraction of the defects survives. The surviving defect fraction is directly related to the density and type of extended defects that act as point defect sinks. Defect partitioning requires the presence of more than one type of sink and that at least one of the sinks has a capture efficiency for either vacancies or interstitials that is different from that of the other sink(s). For example, dislocations provide the interstitial “bias” that drives swelling, and the ratio of the dislocation to cavity sink strength determines the swelling rate. These sink strengths change during irradiation, and an explicit model of their evolution is required to simulate swelling or creep. Such a model has been developed; the influences of various model assumptions and parameters are discussed. The model simulates the evolution of Frank faulted interstitial loops, providing a dislocation source and the glide/climb of the dislocation network leading to annihilation of dislocation segments. Good agreement is found between model predictions and experimental data. Swelling simulations are shown to be quite sensitive to the dislocation model. |
| Databáze: | OpenAIRE |
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