实验时间尺度下纳米晶铁抗辐照损伤性能模拟研究

设计能承受大剂量辐照损伤的核结构材料或找到材料具有最佳抗辐照性能的工作窗口不仅具有重要的意义，也是一个巨大的挑战。纳米晶材料通常呈现出较好的抗辐照性能，但并不是在任何条件下的抗辐照性能都好。实验表明纳米晶/多晶材料的辐照响应与辐照条件（温度和辐照剂量）和晶粒尺寸等因素有关。本课题拟开展"实验时间尺度下纳米晶铁抗辐照损伤性能模拟研究"。以bcc-Fe为主要对象，以跨时间尺度的温度加速的分子动力学为主要模拟手段，结合经典分子动力学、静态计算和激活能谱分析等方法或技术，研究纳米晶铁辐照损伤与修复的结构演化及其动力学过程，澄清多晶和纳米晶材料辐照响应与晶粒尺寸、温度和辐照剂量依赖关系的微观图像。最终在晶粒尺寸、温度和辐照剂量等参数空间中寻找材料抗辐照损伤的最佳运行窗口，为设计、研发和评估抗辐照材料提供有实际意义的信息或数据。

It not only has grat significance and but also is a big chanllenge to design nuclear materials that can sustain a large amount of radiation damage or to find the optimal working window of nuclear materials. Nano-crystallines generally exhibit radiation-resistance, however, the radiation response of which depends on irradiation conditions (temperature and dose) and grain size, indicated by expreiments. We intend to perform "Atomistic Simulations of Radiation-Resistance in Nano-Crystalline Fe at Experimental Time Scales". The bcc Fe is selected as the main model system and the temperature-accelerated dynamics is combined with classical molecular dynamics, molecular statics, and activation energy spectra. The atomic process will be revealed involved in the damage and healing of nano-crystalline Fe; the microscopic picture about the dependence of the radiation response on temperature, dose and grain size will be clarified. A window in the parameter space of temperature, dose and grain size will be sketched out, in which materials show best radiation tolerance. The work will be served as a guide to the design and development and evaluation of radiation resistant materials.