Joining strength and interfacial microstructure of brazing superalloy and 3D-Cf/SiC

The interfacial microstructure and joining strength of GH2907-interlayre, interlayer-Cf/SiC of GH2907 and 3D-Cf/SiC ceramic matrix composite brazed by Nickel-based high temperature brazing filler were researched in this paper. The result indicated that the interlayer thickness of tungsten alloy has great influence on joining strength. According to the experiment condition, the optimum thickness of interlayer is 1.5mm, and the four-point bending strength of joint reaches to 109MPa, meeting the strength requirement of brazing.The joint structure after brazing is: GH2907-(compound of Ni-B and Nickel-based solid solution containing niobium/Tungsten alloy/solid solution of Au-Ni/compound of Ni-Si/layer of Cr3C2 and other carbide)-Cf/SiC. Additionally, the interface between filler metals and Cf/SiC is very tight and the microstructure of tungsten alloy does not change abnormally.