Structural, mechanical, and sand erosion properties of TiN/Zr/ZrN multilayer coatings

• Ti/TiN/Zr/ZrN coatings with different period and the number of cycles were designed.
• The mechanical properties of coatings depend on the period rather than number of cycles.
• Chipping and delamination probably dominate the failure mechanism of coated samples.

TiN/Zr/ZrN multilayer architectures with different period and number of cycles are designed and deposited on TC11 titanium alloys by vacuum cathodic arc ion plating method. Their mechanical, adhesive, and erosive properties are investigated. For the designed architectures with specific thickness, their hardness and critical load depended on the period of coatings, but are not sensitive to the number of cycles. The erosion wear resistance of TC11 substrate can be effectively improved by increasing the period of coating up to 24. The failure mechanism of bare TC11 titanium alloys are dominated by plastic deformation via cutting and plowing, while chipping and delamination probably dominate the failure mechanism of coated samples. Crack deflection and crack branching are also observed in eroded samples.