Thermal Stability And Corrosion Resistance After Annealing Of (Zr,Cr)/(CrN,ZrN) Multilayer Coatings

As the rapid development of industrial production,marine exploration,and the energy sector progresses,more and more critical components need to operate under extreme environments and corrosive media.High temperatures,salt content,and friction wear can greatly limit the service life of these critical components,reducing the reliability and economic efficiency of equipment.CrN and ZrN-based multilayer coatings play a significant role in protecting critical components due to their excellent hardness,wear resistance,and corrosion resistance.In this study,we used multi-arc ion plating deposition technology to prepare Zr/CrN,Cr/CrN,Zr/ZrN,and Cr/ZrN multilayer coatings,and investigated the changes in structure and properties of the multilayer coatings after annealing at 500℃,600℃,and 700℃.The main conclusions are as follows:By adjusting the deposition time of the metal Zr layer,four Zr/CrN multilayer coatings with different modulation periods were prepared and subsequently annealed.The mechanical properties,tribological properties,and corrosion resistance of the annealed Zr/CrN multilayer coatings with different modulation periods were evaluated.The results showed that the Zr/CrN multilayer coatings with modulation periods of 90 seconds and 120 seconds detached from the substrate after annealing at 700℃,while those with modulation periods of 10 seconds and 30seconds remained intact,indicating stronger film-substrate adhesion for the latter.In terms of mechanical properties,the Zr/CrN multilayer coating with a 10-second modulation period exhibited the highest hardness,which decreased after annealing due to stress relaxation and grain growth.Regarding tribological properties,the friction coefficient and wear scar width of the four Zr/CrN multilayer coatings with different modulation periods increased after annealing,which was related to the change in their microstructure.In terms of corrosion resistance,the Zr/CrN multilayer coating with a 10-second modulation period demonstrated the best performance before annealing.After annealing,the corrosion resistance of the Zr/CrN multilayer coating with a 10-second modulation period decreased,but the corrosion resistance of the Zr/CrN multilayer coatings with 30,90,and 120-second modulation periods improved.The hardness of the Cr/CrN multilayer coating increased after annealing,reaching its highest value at 700°C,which was attributed to the formation of more Cr₂N phases in the Cr/CrN multilayer coating during the annealing process.Compared with the Zr/CrN multilayer coating,the Cr/CrN multilayer coating had a lower friction coefficient,which increased gradually with the rise of annealing temperature.On the other hand,the corrosion resistance of the Cr/CrN multilayer coating increased most significantly after annealing at 500°C.Comparing Zr/ZrN and Cr/ZrN multilayer coatings:In terms of coating structure thermal stability,the Zr/ZrN multilayer coating outperformed the Cr/ZrN multilayer coating.In terms of hardness,wear resistance,and corrosion resistance,the Cr/ZrN multilayer coating performed better.However,after high-temperature annealing,the corrosion resistance of the Cr/ZrN multilayer coating decreased,while the corrosion resistance of the Zr/ZrN multilayer coating showed a significant improvement after annealing at 600°C.