金属W中辐照缺陷的产生、演化与热回复机制

Defect Production, Evolution, and Thermal Recovery Mechanisms in Radiation Damaged Tungsten

金属W是核聚变反应堆中面向等离子体部件的主要候选材料。服役期间,钨部件需要承受高温、高通量聚变反应中子轰击带来的辐照级联损伤。这些损伤主要表现为高浓度的点缺陷及团簇。它们与氢氦等离子体、嬗变反应的多种产物相互作用,导致辐照硬化、韧脆转变温度升高、导热能力下降等问题。本文围绕金属W的辐照级联损伤,基于显微缺陷实验表征与材料多尺度模拟计算,系统总结了辐照缺陷的产生、演化与热回复行为及作用机制。这些信息反映了材料中辐照缺陷特征的统计规律,构成定量描述微观损伤组织随时间尺度与空间尺度变化的依据,有利于钨部件性能的预测、服役可靠性评价以及未来新型材料部件的研发。

Tungsten(W) is a prime candidate for use in plasma-facing components in fusion reactors. These components are subjected to high temperatures and displacement damages caused by fusion neutron bombardments. The displacement damages are mainly present as high concentrations of point defects and clusters. They interact with the hydrogen, helium plasma, and various other transmutation products, giving rise to unwanted consequences, such as radiation hardening, increased brittleto-ductile transition temperature, and thermal conductivity degradation. This review focuses on the radiation-induced displacement damage in tungsten and aims to provide a systematic summary of the underlying mechanisms for the production, evolution, and thermal recovery of radiation defect, using defect microscopy techniques and materials multiscale modeling. The information uncovered, reflects statistical laws of radiation defect characteristics;serves as the basis for a quantitative description of time-and space-dependent evolution of damage microstructure;and is in great favor of material property prediction, reliability evaluation, and the future development of novel materials.