Influence of Interlayers on Adhesion Strength of TiN Film on Mg Alloy

Abstract

The wide application of Mg alloys has been restricted because of their poor corrosion and wear resistance. Titanium nitride ceramic films prepared via magnetron sputtering can improve the corrosion and wear resistance of Mg alloys. However, residual stress produced at the interface between the film and the Mg alloy substrate causes the TiN film to spall off and reduces its service life. One potential approach to mitigating residual stress involves enhancing the adhesive strength between the film and the substrate, thereby potentially extending the service life of the film. To increase the adhesion strength between the TiN film and the Mg alloy substrate, a Ti or Al interlayer was deposited on the Mg alloy by magnetron sputtering. Subsequently, the adhesion strengths of TiN/Ti and TiN/Al were determined under a single high shear force by scratch tests and were determined under multiple low shear forces by friction and wear tests. The results of scratch tests show that TiN with the Ti interlayer on the Mg alloy substrate has superior adhesion strength under a single high shear force. And the results of friction and wear tests show that both the TiN/Al and TiN/Ti films provided protection to the Mg alloy substrate against friction and wear, and TiN with the Ti interlayer on the Mg alloy substrate has superior adhesion strength under multiple low shear forces. This work can provide guidance for the selection of interlayers between Mg alloy substrates and hard ceramic films.