Direct joining of 2D carbon/carbon composites to Ti-6Al-4V alloy with a rectangular wave interface

Direct joining of 2D carbon/carbon composites (C/Cs) to Ti-6Al-4V (Ti64) has been studied theoretically and experimentally by constructing a rectangular wave interface (RWI) between C/Cs and Ti64. The joining surface of C/Cs was grooved into a rectangular wave surface, on which a Ti64 layer was then clad at 1680-1710 °C to form a pre-joining clad sample. The clad sample was then diffusion bonded to a Ti64 plate at 900 °C to form a final joined sample. The residual stresses in the clad or joined samples were estimated by Finite Element Analysis. The microstructure of joined sample was examined by SEM, and the strength of joined sample was evaluated by compressive shear strength tests. The simulation results indicated that the residual stresses were more beneficial to crack arrest for the clad or joined samples using the RWI instead of a flat interface. The experimental results showed that the sound joined samples were obtained with the shear strength as high as 41.63 MPa.