Microstructure And Wear-corrosion Resistance Of Nitride Nano Multilayer Coatings

Surface coating technology has been widely used in surface protection,processing and manufacturing,semiconductor,optical devices,decoration and other industries.In this paper,Ti N-based nano-multilayer coatings are deposited by physical vapor deposition(PVD)technology to control the growth structure of the coating,interrupt the growth of columnar crystals,and get the coating with high hardness,high toughness,good adhesion,to improve the protective effect of the hard coating in wear resistance and corrosion resistance,which can significantly improve the wear performance and corrosion resistance of the titanium alloy substrate.The main contents are as follows:Magnetron sputtering coating technology was used to prepare Ti N,Zr N single layer and its nano-multilayer coating,to study the advantages of nano-multilayer over single-layer,and the influence of modulation period(?)on nano-multilayer.Although both single-layer and nano-multilayer coatings have a columnar crystal structure that runs through the entire coating,the Ti N/Zr N nano-layered columnar crystals have small crystal grains,a dense structure,and a flat surface.When?is less than 8.9 nm,the multi-layer coating begins to exhibit coherent epitaxial growth and satellite peaks appear in the XRD pattern.Due to the combination of high hardness and high toughness of Ti N/Zr N nano-multilayer coating,the wear resistance is superior to single layer;the refinement of Ti N/Zr N nano-multilayer grains and dense structure,the corrosion resistance is also superior to single layer.But the Ti N/Zr N nano-multilayer did not interrupt the growth of columnar crystals,which hindered the further improvement of corrosion resistance.When?is 30nm,the wear rate of the coating is the lowest,5.04×10^-6mm³N^-1m^-1,with the best wear resistance;while the?is 8.9nm,the coating reaches the lowest self-corrosion current density(i_corr)(5.13×10^-5A/cm²),with the best corrosion resistance.The coatings with the same?did not reach the optimal corrosion resistance and wear resistance.Considering that arc ion plating has a higher ionization rate,higher ion energy,better coating density,and is beneficial to improve the bonding force between titanium alloy and hard coating;Cr N is better than than Zr N in wear and corrosion resistance.Therefore,using arc ion plating technology to deposit Ti N,Cr N single layer and Ti N/Cr N nano-multilayers coating.The study found that Ti N/Cr N nano-multilayers exhibited higher hardness(24 GPa).The structural of nano-multilayers significantly improved the adhesion compared to single-layer.The wear and corrosion resistance of Ti N/Cr N nano-multilayer coatings are better than single-layer coatings,and they are also improved compared to the previously prepared Ti N/Zr N nano-multilayers.By changing the?,the TiN/CrN nano-multilayer is optimized.The study found that the Ti N/Cr N nano-layered columnar crystal grains were partially interrupted,and no columnar crystal structure was formed throughout the entire coating;as?decreased,the tendency of the grains to grow coepitaxially increased;The hardness value increases with the decrease of the modulation period.When the?is 12 nm,the hardness reaches the highest value of 29.79 GPa;when the?is 17 nm,the Ti N/Cr N nano-multilayer adhesion reaches the maximum value of 45 N.The wear rate increases first and then decreases as the?decreases;Icorr decreases as the?decreases.The Ti N/Cr N nano-multilayer coating with a?of 12 nm has the lowest wear rate(1.18×10^-7mm³N^-1m^-1);and its i_corris also the lowest(1.03×10^-7A/cm²).Therefore,the optimized Ti N/Cr N nano-multilayer achieves the best wear and corrosion resistance in the same?,so that the titanium alloy matrix can obtain the best protection.