射线辐照下材料微结构的演化及其对力学性能的影响

项目名称： 射线辐照下材料微结构的演化及其对力学性能的影响

项目编号： No.11272092

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 霍永忠

作者单位： 复旦大学

项目金额： 82万元

中文摘要： 核环境下材料力学性能的变化是影响核工程安全可靠性的一个主要因素，而宏观性能的变化主要决定于辐射诱发材料内多种微结构在辐照-热-力耦合作用下的演化过程。本课题拟在分析辐照缺陷对材料自由能和缺陷迁移能等热力学性质影响的基础上，结合反应扩散方程和相场方法，建立空洞、气泡等典型辐照微结构的演化方程，并利用已有的辐照实验和原子、分子计算模拟结果，确定或效验演化方程涉及的参数和条件；进而计算分析典型核材料和燃料在辐照下产生肿胀、生长和加速蠕变的过程，找出主要影响因素和变化规律；结合位错动力学和晶体塑性力学理论，分析空洞、气泡等辐照微结构对材料辐照硬化和脆化的影响，从而将辐照微结构作为内变量纳入材料的本构关系。本课题的完成，将有助于弄清辐照诱发的材料力学性能变化的微观机制、主要影响因素和影响规律，为提高核安全和建设先进核反应堆提供理论参考，也能丰富力学中的多场、多尺度研究方法，进一步拓展力学本构理论。

中文关键词： 辐照效应；辐照损伤多尺度模拟；相场模型；形核算法；微动损伤

英文摘要： Irradiation induced degradation of material properties is one of the key safety issues in nuclear engineering. The change of macroscopic mechanical properties is mainly due to the evolution of the irradiation induced microstructures under the radiation-mechanical-thermal coupling. Based on some careful analyses of the effect of the irradiation damages on the free energy of materials and the migration energies of defects, evolution equations of some typical irradiation microstructures, such as voids and inert gas bubbles，will be constructed in the framework of reaction-diffusion equations and phase-field modeling. Some experimental and atomic level simulation results will be used to calibrate the evolution equations. The irradiation induced swelling, growth and creeps of typical nuclear materials and fuels will be studied. Particular attention will be focus on the effect of the microstructure evolutions on the change of the macroscopic mechanical properties. The effect of the irradiation induced microstructures on the hardening and embrittlement of metal alloys will be further analyzed in the framework of dislocation dynamics and crystal plasticity theory. The constitutive equations of materials can be then extended to include the irradiation induced microstructures as internal variables. The research proposed wi

英文关键词： irradiation effect；multi-scale mdeling of radiation damage；phase field modeling；nucleation algorithm；fretting damage