基于扩展的非均匀热浴双温度模型对SiC/SiC界面辐照损伤机理研究

The problem of the irradiation damage in the material is one of the key factors restricting the development of the advanced nuclear energy. Nowadays, the computer simulation based on the accurate theoretical model for different candidate structural materials of the nuclear reactor is one effective approach to explore the irradiation damage and its mechanism. The irradiation damage and the mechanism of the SiC/SiC interface are systematically investigated based on an extended inhomogeneous thermostat two temperature model. The detailed content is organized as follows: (1) An extended inhomogeneous thermostat two temperature model is established, which can be used for accurately describing the processes of the irradiation damage of composite materials; (2) The irradiation damage of the SiC/SiC interface is studied by considering the electronic stopping and the electron-phonon coupling effects; (3) The local heat dependence of the irradiation damage in the SiC/SiC interface is studied during the irradiation processes; .(4) In order to obtain the best radiation resistance performance, the effects of thickness and orientation of the interphase on the irradiation damage of the SiC/SiC interface are also investigated. It is highly expected that the completion of this project can provide a better theoretical model for the description of the irradiation damage process of materials, and also some theoretical evidences for the irradiation damage and the mechanisms of the interface of SiC composites, which will result in a critical step forward for design of the interface of SiC composites.

材料的辐照损伤问题是制约先进核能发展的关键因素之一。基于精确的理论模型对核反应堆不同候选结构材料进行计算模拟是探究材料辐照损伤及其机理的一种有效方法。本项目拟基于扩展的非均匀热浴双温度模型对SiC/SiC界面辐照损伤及其机理进行基础科学研究。具体内容如下:(1) 建立扩展的非均匀热浴双温度模型，使其能够准确描述复合材料辐照损伤过程；(2) 研究电子阻止和电子-声子耦合效应对SiC/SiC界面辐照损伤的影响；(3) 研究辐照过程中局域热对SiC/SiC界面损伤的影响；(4) 研究SiC/SiC界面相厚度和空间取向对界面辐照损伤的影响，以获取SiC/SiC材料抗辐照的最佳结构模型。项目的完成可望为复合材料辐照损伤过程的描述提供可靠的理论模型，并为碳化硅复合材料界面辐照损伤机理提供理论依据，使碳化硅复合材料界面设计前进重要的一步。

核反应堆内材料由于长期受到高能粒子辐照而形成大量缺陷，导致材料性能降低，成为制约先进核能发展主要瓶颈之一。基于计算机模拟方法对不同候选结构材料的辐照损伤行为进行模拟研究是探究反应堆内材料损伤行为及其机理的一种有效方法。本项目结合国内外相关研究现状和项目组现有工作基础，对高能粒子辐照下SiC/SiC界面材料辐照损伤及其机理进行基础科学研究。主要研究内容如下：根据非均匀热浴双温度模型的特点，编写了适用于研究高能粒子辐照下SiC/SiC界面材料辐照损伤的脚本代码，实现了电子阻止和电子-声子耦合效应对碳化硅复合材料辐照损伤过程的影响研究；研究了高能粒子辐照下增强体和基体的损伤行为，阐述了增强体可以有效地保护基体的机理；根据碳化硅复合材料界面相热解碳结构的不确定性，分别研究了石墨烯界面相的辐照损伤行为、具有本征缺陷石墨烯或碳纳米管界面相的离位阈能、碳纳米管的穿透能及其界面相受到高能粒子辐照后的熔合动力学过程。研究结果对揭示SiC纤维增强SiC基体复合材料的抗辐照机制，阐明碳化硅复合材料界面辐照损伤机理，改进界面设计和提高未来核聚变反应堆和先进核裂变系统安全性具有重要理论意义和工程应用价值。