Interfacial reactions and zigzag groove strengthening of C/C composite and Rene N5 single crystal brazed joint

C/C composites are brazed in vacuum to the Rene N5 single crystal superalloy using the AgCuTi filler metal with the flat and zigzag triangular groove interfaces. The structure of the C/C/TiC/Ag(s.s)+Cu(s.s)+Ti(Cu,Ni)/Ti(Cu,Ni)2+Ti(Cu,Ni)3+Ti(Cu,Ni)2/Ni(s.s)/(Cu,Ni)+Ag(s.s)/Rene N5 is formed at the joint interface. The shear strength of the joint with the zigzag triangular groove interface is improved greatly compared to that of the joint with a flat interface. The improvement stems from the reduced residual stress, extended joint area, and enhanced pinning effect.