基于微量元素(Nb、Zr)和TiC协同改性钨基材料的烧结特性与作用研究

As a candidate material for plasma facing material (PFM) , Tungsten exhibits several problems, i.e., difficulties to densify, low recrystallization temperature, low temperature brittleness preventing from its application potential. The key topics about modification and sinteration of tungsten are focused on in this proposal.The project intends to use a specific route to prepare TiC powders coated with tungsten doped by microelements (Nb, Zr),and investigates the sintered behaviour and influencing factors of the multi-component modified materials, realizing the component and distribution of the dispersed phases existed controllably in the grain and grain boundary of the tungsten composites, as a result, the microstructure and properties are improved. The applicant will study systematically the preparing technology of the TiC powders coated with doped tungsten, and investigate the effects of the second phases and the distribution on the sintered features,recrystallization temperature and high temperature stability of the resulted tungsten. In addition,the sintered mechanism and the synergic effects of the microelements with TiC in process of sintering will be discussed, exhibiting the contribution mechanism from microelements and TiC on the strength-ductility of the tungsten matrix materials. Aiming at obtaining the modified tungsten with high level performance, the applicant anticipates to break through the scientific barriers of the sintering and strength-ductility mechanism of the muti-component modification tungsten, providing a new route and theory reference for the preparation and application of high performance tungsten matrix materials facing plasma in fusion reactors.

钨作为面向等离子体候选材料，所面临的烧结致密化困难、再结晶温度低和低温脆性等问题限制了应用潜质，钨材料的改性与烧结是研究的关键问题。本项目采用独特的方法制备微量元素（Nb、Zr）掺杂钨包覆纳米级TiC粉体，研究多元改性钨基材料的烧结行为和控制因素，实现改性钨基材料晶粒内部和晶界处弥散相的组成和分布可控，进一步改善其组织结构和提升力学性能；系统地研究微量元素掺杂钨包覆TiC粉体制备工艺，调查第二相及其分布对钨基材料的烧结特性、再结晶温度、力学性能和高温热稳定性等影响关系，探讨改性钨基材料烧结机理和烧结过程中微量元素、TiC协同作用规律，揭示微量元素与TiC协同效应对于改性钨基材料强韧化的贡献机制。获得具有良好性能的改性钨基材料，期望在钨基材料烧结和强韧化机制等科学问题研究方面有所突破，为高性能面向等离子体钨基材料制备与应用提供新思路和理论参考。

本项目采用了独特的方法制备微量元素（Nb、Zr）掺杂钨包覆纳米级TiC粉体，研究了多元改性钨基材料的烧结行为和控制因素，实现了改性钨基材料晶粒内部和晶界处弥散相的组成和分布可控，进一步改善其组织结构和提升力学性能；系统地研究微量元素掺杂钨粉体制备工艺，第二相及其分布对钨基材料的烧结特性、再结晶温度、力学性能和高温热稳定性等影响关系，探讨了改性钨基材料烧结机理和烧结过程中微量元素协同作用规律，揭示了微量元素对于改性钨基材料影响规律。