面向PFM的W-Cu梯度功能材料的湿化学近净成形制备和组织性能研究

Abstract: Powder metallurgical W–Cu alloys have been used in electrical contacts, welding electrodes, thermal management devices such as heat sinks，spreaders and many other applications because of their excellent mechanical property, low thermal expansion and high electrical conductivity. The purpose of this project is to develop W-Cu composites with graded distribution of W (Cu) composition (content) to further improve their properties and extend their application to heat sinks for large power electrical components and plasma facing materials (PFM). The main research issues include: (1) optimizing the design of the W-Cu functionally graded materials, including their geometry, composition, microstructure and parameters of their preparation process; (2) developing wet chemical methods such as homogeneous precipitation, gelatification-reduction, Glycine-nitrate process, for synthesizing superfine W–Cu powders, and develop soft chemical methods such as lamination, tape casting, for preparing the W–Cu functional graded materials (FGM); (3) investigating the microstructure, thermal, mechanical, as well as thermo-mechanical properties of the W-Cu FGMs; (4) revealing the correlations among the composition, microstructure, property an preparation process of the W-Cu FGMs; (5) surveying interfacial behaviors and stability of thermal, electrical and thermo-mechanical properties of the FGMs for plasma facing materials (PFM) applications and in some other critical work conditions. .This project will develop novel preparation techniques of W-Cu FGMs with good thermal and mechanical properties, especially some wet chemical methods for superfine W-Cu powders, as well as for the W-Cu FGMs. The key factors that affect the microstructure and properties of the FGMs will be revealed. Therefore, this work is theoretically and technically significant to the development of advanced W-Cu composites, and will widen the applications of W-Cu composites and increase reliability of the materials in some critical applications.

以发展面向等离子体材料（PFM）和大功率微波器件的热沉材料为背景，研制沿截面具有梯度成分分布的W-Cu梯度功能材料；利用有限元分析进行梯度功能材料的成分结构设计；发展以均相沉淀、凝胶还原等液相法为主的超细W-Cu复合粉体的合成工艺，以及轧膜流延为主的湿化学净成形方法；考查W-Cu梯度材料的成分微结构，进行应用条件下的组织性能评价；查明材料组成、结构、性能与制备工艺间的关系；重点查明工作条件下W-Cu梯度功能材料的温度及应力分布特性、材料的结构和性能稳定性，建立相关的性能可靠性评价机制。项目的开展可以丰富W基难熔金属复合材料、梯度功能材料净成形的基本理论和工艺，为高性能梯度W-Cu材料制备与应用提供新思路，为面向高性能电工电子器件及面PFM应用的W-Cu材料的开发提供理论基础和实践积累。

本项目针对聚变堆中面向等离子体部件材料（PFM）与Cu热沉材料之间连接的W-Cu材料和高性能电工电子器件等领域应用的W-Cu材料的服役条件要求，进行W-Cu梯度功能材料（FGMs）结构的优化设计，发展了多种W-Cu梯度功能材料（W-Cu FGMs）的原料W-Cu复合粉末的合成工艺，探索了轧膜、流延、液相沉降胶凝成形等湿化学近净成形制备W-Cu FGMs的工艺方法，系统开展了材料的制备工艺与梯度组织形成、微观组织结构、性能等的研究，重点开展了面向热核聚变装置 PFM 的W-Cu 梯度热沉材料的导热性能、热震性能及抗辐照性能等的研究。.项目的重要研究结果包括：获得了多种超细（纳米）W-Cu复合粉体的高效制备方法以及W-Cu FGMs的湿化学近净成形制备工艺，查明了W-Cu FGMs的制备工艺参数与材料微观组织结构及性能之间的内在关系，揭示了高热冲击和辐照条件下W-Cu FGMs的相关性能和失效行为；针对面向等离子部件不同部位服役条件的不同，创新性地提出在W-CuFGMs结构中复合具有高导热性金刚石相的设计，并获得了金刚石/W-CuFGMs复合材料制备工艺、组织性能等的原创性研究结果。.项目全面完成了各项计划任务，项目执行过程中发表研究论文13篇（其中SCI收录论文10篇），获得授权发明专利3项，另申报处于实审的发明专利3项，参加国内外学术会议6人次，作会议报告4人次，培养博士生5人，硕士生4人。项目解决了W-Cu 梯度功能材料的湿化学近净成形制备、材料组成、微结构和性能调控，以及面向 PFM热沉应用条件下的 W-Cu 梯度功能材料的组织结构变化和热物理性能调控等的关键科学问题，在湿化学近净成形制备梯度 W-Cu 材料的材料化学和工艺基础、烧结行为、组织性能调控、特定服役条件下的材料组织性能演变机制等科学问题研究上取得了具有创新性的研究成果，为面向等离子体材料和部件等应用的高性能梯度W-Cu材料的研究提供理论基础和实践积累，同时丰富了复合材料和梯度功能材料的设计、组织结构、热物理机械性能的基本理论。