Effects of Microstructural Factors on Irradiation Growth in Zirconium-Niobium Alloys
SourceThe irradiation growth mechanism of Zr-Nb alloys has been evaluated on the basis of a growth model in which point defect parameters obtained by molecular dynamics are used.
In the proposed growth model the effects of an acceleration of interstitial flow to the grain boundary are considered. This phenomenon is caused by specific microstructures in the Zr-Nb alloys. Experimental irradiation growth data for specimens with various microstructures were analyzed with the model. The calculated results indicated that the growth rate of Zr-Nb alloys, which became either positive or negative depending on the microstructures, could be simulated by this model adjusting the interstitial in-flow acceleration factor. Further negative growth rate was attributed to the increase of interstitial in-flow to the grain boundaries with specific orientations.