Search academic texts

Information × Registration Number 0223U003771, 0122U202110 , R & D reports Title Precipitation/dissolution of secondary phases and segregation/clustering of point defects in Zr-Nb-Sn alloys during solid solution annealing and neutron irradiation of the annealed sample popup.stage_title Head Kharchenko Vasyl O., Доктор фізико-математичних наук Registration Date 29-06-2023 Organization Kharchenko Vasyl O. popup.description2  The work is devoted to the study precipitation of secondary phases in binary and ternary zirconium-based alloys with low content of alloying elements within the framework of the phase field approach. A phase field model was developed and applied to study precipitation in a model of commercial Zr-1%Nb-1%Sn and Zr-2%Nb alloys during heat treatment. Analysis of the local rearrangement of alloying elements and equilibrium vacancies during precipitation showed that the dissolved tin segregates mostly around the interphase boundaries by capturing vacancies. When studying the precipitation kinetics, sizes and distribution of precipitates, it was found that the Lifshits-Slozov-Wagner distribution can be used to predict the statistical properties of precipitates. Modeling of the evolution and radiation-induced precipitation of new precipitates during neutron irradiation of zirconium alloys with low content of alloying elements was carried out within the framework of the developed phase field model, by taking into account ballistic mixing and the dynamics of point defects with their sinks (dislocation loops). It is shown that in a sample that initially contains precipitates of the secondary phase, irradiation leads to the dissolution of precipitates at low doses and the growth of new ones with the accumulation of the dose. An analysis of the dynamics of radiation-stimulated precipitation and statistical distributions of precipitates with local rearrangement of non-equilibrium vacancies around the precipitates was carried out. It is shown that the competition between ballistic mixing and thermodynamic force plays a major role in the kinetics of radiation-induced precipitation and dissolution of precipitates. Product Description popup.authors popup.nrat_date 2023-06-29 Close