C_f/SiC复合材料与Nb合金的连接

Joining of C_f/SiC Composites With Niobium Alloy

利用熔盐反应法在Cf/SiC复合材料表面锆金属化的基础上,用TiCuZrN i非晶钎焊箔实现Cf/SiC复合材料与Nb合金钎焊连接。研究发现Cf/SiC复合材料表面Zr金属化层主要的物相为Zr、Zr3O、ZrC和Zr2Si;钎料对Zr金属化层的润湿性良好,钎料中活性元素Ti向Cf/SiC复合材料一侧明显扩散并发生化学反应,实现了钎料与Cf/SiC复合材料的良好键合,并且可以深入Cf/SiC复合材料孔隙形成"钉扎"效应;接头剪切强度达124 MPa,750℃热冲击5次后剪切强度达70 MPa;断裂部分发生在Cf/SiC复合材料与钎料界面处,部分位于Cf/SiC复合材料近缝区。

Based on the zirconium metallized coating on Cf/SiC composites surface by molten salt reaction, Cf/ SiC was brazed with niobium alloy by using TiCuZrNi amorphous filler metal. The results show that the compositon of the coating includes Zr, Zr3O,ZrC and Zr2Si;the metallic coating can be wetted well by liquid filler metal, the active element titanium concentrates towards Cf/SiC and reacts with it, and makes the filler metal strongly joined with the Cf/ SiC, the liquid filler metal can infiltrate into the pores of Cf/SiC to increase the contact area; the shear strength of the brazing joints is up to 124 MPa,the shear strength is up to 70 MPa after 5 times of thermal shock from RT to 750℃ ; and the fracture happened partly at the interface of Cf/SiC composites and filler metal while partly at the Cf/SiC composites near the weld.