【摘要】 设计了钨/石墨烯/钨和钨/石墨烷/钨纳米层状复合材料作为热核聚变装置面向等离子体材料,利用第一性原理计算对氦原子填隙和钨空位形成能以及力学性质进行分析.计算结果表明,石墨烯和石墨烷能够捕获钨基金属中的氦填隙原子和钨空位结构缺陷,钨/石墨烯或钨/石墨烷界面可以提供钨自间隙原子与钨空位复合位点,两种纳米层状复合材料具有“自修复”性能.基于Fukui函数,可认为上述特性与钨/石墨烯或钨/石墨烷界面钨原子位点反应活性的变化有关.另外,石墨烯可以提高钨基金属的延展性,降低其各向异性.更多还原

【Abstract】 Tungsten/graphene/tungsten and tungsten/graphane/tungsten nanolayered composites were developed and applied as the plasma facing materials of nuclear fusion devices. The formation energies of the helium interstitial atom and tungsten vacancy and the mechanical properties of the two nanolayered composites were investigated by first-principles calculation. The results indicate that the tungsten/graphene/tungsten and tungsten/graphane/tungsten nanolayered composites exhibit resistance to radiation damage to some extent. The tungsten/graphene and tungsten/graphane interfaces serve as sinks for both the helium interstitial atom and tungsten vacancy and as sites for the selfhealing performance of tungsten self-interstitial and vacancy. The results based on the Fukui function reveal that these features of the tungsten/graphene and tungsten/graphane interfaces are associated with the change in the activity of tungsten atoms. An interesting finding of this study is that the ductility of tungsten-based materials can be enhanced and the anisotropy factor reduced by inserting monolayer graphene into the tungsten crystal.更多还原