基于多机制复合效应的Cf/SiC复合材料与GH3044高温合金连接基础研究

研究内容和意义：针对Cf/SiC复合材料与高温合金耐高温连接需求，提出并研究一种基于反应-复合钎焊、TLP和PTLP复合效应的低应力、耐高温连接方法——“多机制复合扩散钎焊”。着重围绕Cf/SiC复合材料与高温合金多机制复合扩散钎焊所涉及的两个关键基础问题即“连接反应行为及机理”——液相(Cu-Ti)/C反应、复合材料/连接层界面反应行为及机理和“成分均匀化动力学”——连接层金属基体与高温合金母材之间、连接层内Ni颗粒与金属基体之间扩散动力学等开展系统研究，为Cf/SiC复合材料与高温合金多机制复合扩散钎焊接头力学性能与耐热性能的兼容调控奠定理论基础。.特色与创新：多机制复合扩散钎焊是一种新的“低温连接/高温服役”连接方法，兼具复合钎焊、TLP和PTLP的优势，且其中的粉末PTLP过程在动力学上属于大扩散面积、短扩散距离的快速机制，其方法思维对陶瓷类材料与金属的耐高温连接具有普遍意义。

In accordance with the high temperature resistant demand for joining Cf/SiC composite and superalloy, this project presents a multi-mechanism composite-diffusion brazing process to achieve Cf/SiC composite / GH3044 superalloy joint with low internal stress and high temperature tolerance, which is based on reactive composite brazing, transient liquid phase bonding (TLP) and partial transient liquid phase bonding (PTLP). In order to lay a theoretical foundation for process optimization and compatible regulation of the mechanical properties and heat resistance of the joint, this investigation puts stress on two critical fundamental issues, i.e., “interfacial reaction behaviors and mechanism” and “composition homogenization kinetics”. The former involves (Cu-Ti) / C particles liquid / solid reaction and Cf/SiC composite / interlayer interfacial reaction. The latter refers to the diffusion between Ni particles and the metal matrix in the interlayer, and the diffusion between the metal matrix and GH3044 superalloy substrate. .The multi-mechanism composite-diffusion brazing process is a novel joining technology with the characteristic of “low bonding temperature/high applicable temperature”, which combines the advantages of composite brazing, TLP and PTLP. Particularly, the PTLP process involved belongs to a fast kinetics mechanism with large diffusion area and short diffusion distance. The ideas and method of this study will be universally available for joining other ceramics and their composite materials to metals in high temperature applications.