Comparative tribological behavior of TiN monolayer and Ti/TiN multilayers on AZ31 magnesium alloys

The TiN monolayer and Ti/TiN multilayers were prepared on the AZ31 magnesium alloys by filter cathodic vacuum deposition. The TiN monolayer with highest hardness among the coatings failed during friction as its poor resistance to crack propagation, low toughness, and poor deformation coordination between the coating and substrate. The Ti/TiN multilayers with layered structure had lower hardness but withstood the friction process due to their higher toughness, better resistance to crack propagation and good deformation coordination between the coating and substrate. The layer by layer wear mechanism was revealed through observing the crosssectional SEM morphology of the wear track of the Ti/TiN multi-2 coating. Compared with the Ti/TiN multi-2 coating, the Ti/TiN multil-6 coating with higher flow rate of nitrogen introduction had lower wear rate as its higher hardness but produced brittle cracks.

Automated summary

In this study, TiN monolayer and Ti/TiN multilayer coatings were prepared on AZ31 magnesium alloys by filter cathodic vacuum deposition, and their performance and wear mechanism during friction were investigated. The results show that although the TiN monolayer had the highest hardness, it failed during friction due to its poor resistance to crack propagation and poor deformation coordination with the substrate. On the other hand, the Ti/TiN multilayer coatings, with higher toughness, better resistance to crack propagation, and good deformation coordination with the substrate, were able to withstand the friction process.