基于高温应用的ZrB2-SiC复相超高温陶瓷焊料体系设计与界面反应机制研究

项目名称： 基于高温应用的ZrB2-SiC复相超高温陶瓷焊料体系设计与界面反应机制研究

项目编号： No.51202270

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 无机非金属材料学科

项目作者： 张辉

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 25万元

中文摘要： 超高温陶瓷(UHTCs)在航空航天热防护领域具有重要应用前景，其中ZrB2-SiC是最有潜力候选材料之一。受制备工艺和装备条件限制，难以直接制备大尺寸复杂形状UHTCs部件，而通过焊接则易实现。目前UHTCs焊接研究主要为低温金属焊接，而这与UHTCs高温应用背景相悖。本项目以ZrB2-SiC为研究对象，开展旨在提高结合强度和降低残余应力的Zr-Mo-B基高温焊料体系的组成设计、制备及焊接界面反应机制研究。通过对高温焊料体系高温润湿行为及其焊接反应产物研究，实现低残余应力高温焊料体系的组成设计；通过对焊料浆料流变性及其流延成型工艺研究，实现成分分布均匀、厚度均一Zr-Mo-B多组分薄膜焊料的可控制备；通过对焊料和基体界面在高温焊接过程物理化学行为的研究，阐明焊料在焊接界面反应层的元素分布及微观结构演化行为，揭示界面反应机制和高温焊接机理，为ZrB2-SiC基材料在国防领域未来应用奠定基础。

中文关键词： ZrB2-SiC；高温焊接；焊料设计；界面反应；微观结构

英文摘要： ZrB2-SiC ceramics, which belong to a group of materials identified as ultra-high temperature ceramics (UHTCs), are one of the most promising materials for thermal protection system in the hypersonic vehicles. In effect, large size and complex-shaped components are difficult to fabricate directly by coventional ceramic processing procedures owing to the available equipments such as sintering furnace, machining equipments and so on. However, it is easy to make it by ceramic brazing method. Recently, several metals such as Ni, Ag, Cu, Pd, and etc., are reported to join UHTCs successfully by brazing, but the low brazing temperature and high residual stresses hinder the applications of UHTCs. Therefore, it is necessary to investigate the high temperature brazing of ZrB2-SiC ceramics with low residual stresses. This project mainly focuses on the composition design and fabrication of Zr-Mo-B high temperature brazing filler and the mechanism of interfacial reactions in order to improve the brazing strength and reduce the residual stress. Firstly, the high temperature contact behaviors of brazing filler and brazing products are investigated to optimize the ingredient of brazing filler. Secondly, the rheological properties of Zr-Mo-B slurry are investigated to get stable filler slurry. Then the Zr-Mo-B film brazes with u

英文关键词： ZrB2-SiC；brazing；design；interfacial reaction；microstructure