微纳复合增强细晶钨及其作用机制

Tungsten has been determined as the full-divertor material for the plasma-facing components in the international thermal experiment reactor(ITER) and China Fusion engingering testing reactor(CFETR)due to its high melting point, low sputtering rate and low H retention. However,traditional tungsten can not meet the fusion requirement under the high heat flux above 10MW/m2， because of its intense temperature sensibility and brittleness due to its coarse grain and high ductile brittle transition temperature (DBTT)，lower recrystallining temperature. Adding minor rare earth oxide or carbides has great advantages in enhancing high heat loading resistance of tungsten, here,trace micro/nano oxides and carbides particles are designed to dispersion-strengthening and refine tungsten grain by using micro-nano particle compositing technology via sol-nonuniform phase recipitation-spraying and strengthening sintering to preparing fine grain tungsten material with enduring high heat loading.The strengthening mechanism and high heat impacting behavior will be investigated here,the interaction between tungsten and tungsten,tungsten and micro-nano particleamong micro-nano particles, and its functional mechanism in densification and inhibiting tungsten grain growth,will be revealed.The effects of micro-nano particle composite on the performance and the resistance to high heat loading of tungsten will be deeply studied from the experimental point of view. The first principle,molecule-dynamics will also be applied to computate the interface bonding energy between tungsten and tungsten phase as well as tungsten and micro-nano particle phase, so as to forecast and reveal the influence mechanism of micro-nano particle to the mechanical properties and resistance to high heat loading property.

钨具有高熔点、低溅射、对H滞留低等特性，被确定为ITER国际热核聚变堆和我国未来热核聚变堆面向等离子体全钨偏滤器材料。然而，现有钨材料因组织粗大、性能低、塑脆转变温度高、再结晶温度低，不能满足未来聚变堆在10MW/m2以上高能电子束冲击下的抗高热负荷要求。添加微量稀土氧化物/碳化物显示很大潜力，本项目设计用微量稀土氧化物和碳化物微纳复合强化，用溶胶-非均相沉淀-喷雾干燥实现微量粒子与钨纳米原位复合和强化烧结制备细晶钨材料，研究其强韧化机制、抗高热负荷行为与失效机制。揭示微量稀土氧化物、碳化物与钨的相互作用及其对致密化晶粒抑制的作用机理，从实验研究微纳复合对钨材料高温强韧性和抗高热负荷冲击性能的影响和作用机制；采用第一性原理、分子动力学等从理论上研究细晶W/W、钨/纳微粒子相界面结合行为及高能电子束轰击对界面行为的影响。通过实验与理论结合，更深层次预测和揭示微纳粒子对钨强韧化与抗高热负荷影响

钨具有高熔点、低溅射、对H滞留低等特性，被确定为ITER国际热核聚变堆和我国未来热核聚变堆面向等离子体全钨偏滤器材料。然而，现有钨材料因组织粗大、性能低、塑脆转变温度高、再结晶温度低，不能满足未来聚变堆在10MW/m2以上高能电子束冲击下的抗高热负荷要求。添加微量稀土氧化物/碳化物显示很大潜力，本项目设计用微量稀土氧化物和碳化物微纳复合强化，用溶胶-非均相沉淀-喷雾干燥实现了微量粒子与钨微纳复合和强化烧结制备细晶钨材料，研究了其强韧化机制、抗高热负荷行为、抗离子辐照行为与失效机制。揭示了微量稀土氧化物、碳化物与钨的相互作用及其对致密化晶粒抑制的作用机理，从实验研究了微纳复合对钨材料高温强韧性和抗高热负荷冲击性能的影响和作用机制；采用第一性原理、分子动力学等从理论上研究了细晶W/W、钨/纳微粒子相界面结合行为及高能电子束、He离子轰击对界面行为的影响。建立了细晶钨的微纳复合强韧化机制。通过本项目研究，建立了微纳复合强化细晶钨块材制备的关键技术和性能数据库，为未来聚变堆提供材料工程的技术支撑；为未来核聚变钨材料制造提供一种全新技术和理论支撑；初步建立该钨合金的热、力学性能数据库，为我国聚变堆的设计提供数据基础。