ABSTRACT We study microstructure transformation in Zr–Nb system under neutron irradiation and its mechanical properties change under mechanical loads in a form of shear deformation by using phase field methodology. The developed phase field approach takes into account defects dynamics based on reaction rate theory and elastic contribution to study mechanical properties change. A numerical modeling is provided in three stages: sample preparation, irradiation of the prepared sample and mechanical loading of the irradiated sample. A precipitation of β-Niobium particles of the size of several nanometers is discussed. Results of phase field modeling indicate that β-Niobium particles grow slowly during irradiation due to point defects rearrangement. Statistical analysis of dynamics of radiation-induced microstructure transformations is provided. Simulation results of shear deformation of pre-irradiated and post-irradiated alloys are discussed. Maps of local distribution of strain and stress and strain–stress curves are obtained. Results are verified with experimental data.

中文翻译：

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中子辐照下 Zr-Nb 合金中 β 相的相场析出和力学性能变化

摘要 我们研究了 Zr-Nb 体系在中子辐照下的微观结构转变及其力学性能在机械载荷下以剪切变形的形式变化，采用相场方法。开发的相场方法考虑了基于反应速率理论和弹性贡献的缺陷动力学，以研究机械性能变化。在三个阶段提供数值建模：样品制备、制备的样品的辐照和辐照样品的机械加载。讨论了几纳米大小的 β-铌颗粒的沉淀。相场模型的结果表明，由于点缺陷重排，β-铌颗粒在辐照过程中生长缓慢。提供了辐射诱导的微观结构转变动力学的统计分析。讨论了辐照前和辐照后合金剪切变形的模拟结果。可以获得应变和应力以及应变-应力曲线的局部分布图。结果用实验数据验证。