Anti-adhesion mechanism of TiB2 deposited Ti6Al4V blade tip against Al-hBN seal coating during high-speed rubbing

The TiB 2 coating deposited by magnetron sputtering on the Ti6Al4V simulated blade tip with a dense fiber-like microstructure has the adhesion strength grade of HF1 . High-speed rubbing results showed that the TiB 2 coating could inhibit the adhesive transfer of the Al-hBN seal coating at 300 m/s. It was found that the tribological oxidation of TiB 2 coating led to the TiB 2 /fused Al interface reaction by characterization of the interface microstructure of the Al-adhesive blade tip. The thin interface reaction interlayer mainly consists of TiAl 3 phase. The large thermal stress at TiAl 3 /TiB 2 interface makes the interface reaction layer with the Al-adhesive transfer layer easily peel off from the blade tip. Thus, the Al-adhesive transfer is always at a lower level.