Rare earth modified reduced graphene oxide reinforced AgCuTi composite brazing filler for brazing C/C composites

Abstract

In order to solve the formation of brittle compounds in brazed joints, an innovative rare earth modified reduced graphene oxide reinforced AgCuTi composite brazing filler was designed to achieve brazed joints with Ag-Cu eutectic as the main organization almost free of brittle compounds, and at the same time, the dispersion of graphene in the joint interfaces was improved. Microanalysis and discussion of the brazing fillers with and without Ce modification showed that the Ce modified reduced graphene oxide was more uniformly dispersed in the brazing fillers. The interfacial microstructures of C/C composites-C/C composites joints with and without Ce modified brazing fillers were compared, and the effect of graphene content on the organization and properties of the joints was investigated. The results showed that the shear strength of the joints was significantly enhanced by using Ce modified brazing fillers. When the graphene content was 0.5 wt.%, the average shear strength of the brazed joints obtained by using Ce modified brazing fillers was 31.82 MPa, increased by 50%.

摘要

为了解决钎焊接头中脆性化合物的形成问题, 我们设计了一种创新性的稀土改性还原氧化石墨 烯增**AgCuTi 复合钎料, 进而获得了以Ag-Cu 共晶为主要组织且脆性化合物生成量合适的钎焊接头。 对比分析了有无稀土Ce 改性的复合钎料的成分和显微组织, 结果表明, 经Ce 改性后的还原氧化石墨 烯在钎料中更加均匀分散。比较了分别采用有无Ce改性的钎料钎焊C/C复合材料-C/C 复合材料接头的 界面微观结构, 并研究了石墨烯含量对接头组织和性能的影响。结果表明, 由于经Ce改性的钎料中的 还原氧化石墨烯分散性更好, 从而细化了焊缝组织, 且物相分布更均匀, 使得接头的剪切**度明显提 高。当石墨烯含量为0.5 wt.%时, 使用Ce 改性的钎料所得钎焊接头的**均剪切**度最高, 为 31.82 MPa, 提高了50%。