Effect of Laser Treatment on Surface and Interface of Silicon Nitride Coated Ti6Al7Nb Alloy – A Statistical Analysis

The current research work investigates the impact of laser treatment on Silicon Nitride (SiN) coating and its performance in the bio-tribological environment. The Cathodic Arc Deposited (CADed) SiN coating over the bio-grade TiAlNb alloy is post-treated with a Yb-doped fibre laser beam. The biocompatibility, surface morphology, and physio-chemical properties of the laser-treated SiN surface are examined. The laser treatment on the SiN surface improved the microhardness above 11 times compared to the TiAlNb alloy. The residual stress of the SiN coating is reduced by the laser treatment and it increased the anti-friction film to reduce the wear. The effect of tribo parameters on the laser-treated SiN-coated TiAlNb alloy is studied and the wear mechanism at the tribo-interface is examined using the SEM morphology. The cause and consequences due to the transition of the wear mechanism are revealed using the wear map in the aspect of bio-tribo conditions.