辐照条件下纯金属及其合金材料的力学性能研究

本项目拟针对纯金属及合金材料，通过实验表征、数值模拟、理论建模三种研究手段，从微观尺度、细观尺度和宏观尺度开展辐照硬化、脆化、蠕变以及疲劳四个方面的研究。首先，通过分子动力学等多种模拟计算手段，从微观尺度模拟分析金属材料中缺陷的形成过程，建立辐照率、辐照剂量等与缺陷种类和数量之间的定量关系，并与实验测量的缺陷信息结果比较。然后，基于细观尺度的位错动力学开展缺陷与位错的相互作用研究，以晶体塑性理论为桥梁，通过有限元模拟、细观力学等方法建立微、细、宏观之间的跨尺度理论框架。最后，基于力学实验的测试结果，验证其合理性。本项目的研究为预测材料性能演化规律、设计具有良好性能的抗辐照材料提供可靠的依据和支撑，也为具有自主知识产权的中国低活化马氏体钢（CLAM钢）机制分析和力学性能进一步优化奠定基础。

In terms of the pure metals and alloys, we analyze the irradiation effect on the mechanical properties at micro-, meso- and macro-scale, which mainly include irradiation hardening, embrittlement, creep and fatigue by three methods (i.e., experimental testing, theoretical prediction and numerical simulation). First, at the micro-scale, the detailed processes of defect formation are simulated by several numerical simulation methods like molecular dynamics simulation, which can help understand the relationship between radiation parameters and the defects information. The corresponding results can be effectively compared with experimental results. Then, at meso-scale the interaction between dislocations and defects will be investigated by the dislocation dynamics. A theoretical model concerning micro-, meso- and macro-scales based on the finite element simulation, self-consistent method and the crystal plasticity theory is established. Finally, the generality and accuracy of the proposed multi-scale model are validated by comparing with the corresponding experimental results. This project aims at predicting the mechanical behaviors of irradiated metals, and has a great significance for designing anti-irradiation materials. Furthermore, this project will pave the way to the mechanism analysis and the improvement of the material performance of China Low Activation Martensitic (CLAM) steel.