In the condition of bonding temperature 1200℃, TLP bonding experiments of DD6 nickel-based single crystal superalloy are conducted by using Ni-8Co-4Cr-0.5W-3.2B interlayer alloys which were prepared by rapid solidification equipment. The time of isothermal solidification and solid state homogenization stage was calculated, and the diffusion distances of melting point depressant element B was computed, which was respectively 6.4h, 9.6h and 170 μm. The results indicate that, the isothermal solidification join...