氦辐照条件下金属材料的力学行为研究

Helium (He) bubbles can be produced in metallic materials through nuclear transmutation reactions during the high energy irradiation process, and the plastic deformation behavior of irradiated materials can be significantly affected by the presence of He bubbles. In terms of single crystal/polycrystal copper and China Low Activation Martensitic (CLAM) steel, we intend to analyze the He hardening and embrittlement of irradiated metals by experimental characterization, theoretical modeling and numerical simulation. For experimental characterization, the microstructure and mechanical properties of metallic materials with/without helium ion irradiation will be studied. For theoretical modeling, constitutive relations and He embrittlement fracture model will be established to quantitatively describe the macroscopic mechanical behavior of He irradiated metallic materials. For numerical simulation, the crystal plasticity finite element method will be established to study the transition process from transgranular to intergranular fracture of He irradiated metallic materials. The purpose of this project is to systematically evaluate the effect of helium on the strength and toughness of metallic materials, and provide theoretical guidance for the design and optimizing of anti-irradiation materials.

金属材料在辐照过程中会发生嬗变反应，在材料内部形成氦泡，进而影响金属材料的宏观力学行为。本项目拟针对单晶/多晶铜和中国低活化马氏体钢（CLAM钢），通过实验表征、理论建模和数值模拟三种研究手段，开展金属材料的氦硬化和脆化研究。在实验表征方面，研究氦离子辐照前后金属材料的微观结构和力学性能的变化；在理论建模方面，建立能够定量描述含氦泡金属材料宏观力学行为的本构关系，以及金属材料氦致脆化断裂模型；在数值模拟方面，建立多晶材料氦致沿晶断裂的有限元模拟体系，并研究氦影响下多晶材料由穿晶材料向沿晶断裂的转变过程。本项目旨在系统评估氦对金属材料强度及韧性的影响，为抗辐照金属材料的优化设计和性能改善提供理论指导。

辐照条件下金属材料力学性能研究对核能的发展至关重要。本项目针对单晶和多晶材料，结合理论建模、数值模拟和实验验证三种研究手段，开展了氦辐照影响下金属材料的力学行为研究。通过考虑氦泡内压的影响，推导了含内压孔洞屈服势函数，建立了含氦泡单晶材料本构关系，系统分析了内压对金属材料变形行为的影响；建立了基于位错运动的双向氦输运模型，定量给出了位错运动和塑性变形过程中晶界氦原子富集现象之间的联系；进一步，结合氦损伤晶界本构关系，建立了金属材料氦致脆性断裂多尺度力学模型，研究了不同氦浓度情况下金属材料的断裂行为，并通过实验验证了模型的合理性。本项目对深入理解及研究金属材料力学行为的辐照效应具有重要的意义。依托本项目已发表SCI论文8篇，包括JMPS和IJP等。