弥散颗粒和纳米晶协同强化钨合金的制备及其高稳定性机理研究

Tungsten-based materials are the most potential candidates that can be applied as the plasma facing materials in future fusion reactors. However, the current developed W-based materials still have some disadvantages including the low strength and insufficient thermal stabilities, which can’t meet the stringent requirements in fusion devices. In order to settle these problems, this project is to fabricate W-0.5wt%ZrC-Ti alloys with nano-grains (<100 nm) and homogeneously dispersed nano ZrC particles through utilizing the “nanoscale W/Ti phase separation” mechanism, using the high energy ball milling and powder metallurgy technique and optimizing process parameters. It is to investigate the evolution of grain size with the Ti content, to get the optimal Ti content and to elucidate the refining mechanism of the tungsten grain size to nanoscale. It is also to characterize the thermal stabilities, mechanical properties and thermal shock resistances, to analyze the microstructures and to clarify the mechanisms of thermal stabilities and synergy strengthening effects in this nanocrystalline W-0.5wt%ZrC-Ti material. The achievements of this project will afford scientific basis for developing high performance W-based materials and their applications as first wall materials in future fusion devices.

钨基材料是最有潜力的能够应用于未来聚变装置面向等离子体材料，但目前发展的钨基材料仍然存在强度低、热稳定性不足的问题，不能满足聚变堆苛刻服役环境需求。针对这些问题，本项目以W-0.5wt%ZrC-Ti体系为研究对象，利用“纳米尺度下W/Ti相分离”原理，通过高能球磨和粉末冶金方法，优化工艺参数，制备出W晶粒尺寸在100nm以下和纳米ZrC颗粒均匀分散的W-0.5wt%ZrC-Ti体系合金块材。研究W晶粒尺寸随Ti含量的演化规律，获得最佳的Ti含量，阐明W晶粒纳米化机理。表征材料的热稳定性、力学性能和抗热负荷冲击性能，并结合微观结构分析阐明纳米晶W合金的热稳定机理以及W晶粒纳米化后弥散颗粒和纳米晶协同强化机理。项目研究成果将为研发高性能钨基材料并为其在未来聚变装置面向等离子体第一壁材料的应用提供科学依据。

钨基材料是最有潜力的能够应用于未来聚变装置面向等离子体材料，但目前发展的钨基材料仍然存在强度低、热稳定性不足的问题，不能满足聚变堆苛刻服役环境需求。针对这些问题，本项目以W-ZrC/Y2O3-Ti/Re合金材料为研究对象，优化了ZrC、Y2O3、Ti、Re添加量，获得了Ti在非平衡状态下完全固溶进入W基体中并形成 W(Ti)-ZrC/Y2O3纳米晶合金粉体的最佳制备工艺，并发展了高致密W-ZrC/Y2O3-Ti合金块材的烧结工艺，利用高能球磨和粉末冶金方法成功制备出W晶粒尺寸在100nm以下和纳米ZrC颗粒均匀分散的W-0.5wt%ZrC-Ti体系合金块材。研究材料的热稳定性、力学性能和抗热负荷冲击性能，并结合微观结构分析阐明纳米晶W合金的热稳定机理以及W晶粒纳米化后弥散颗粒和纳米晶协同强化机理。项目研究成果为研发高性能钨基材料并为其在未来聚变装置面向等离子体第一壁材料的应用提供科学依据。