Research On Surface Functionalized Structure Design And Performance Of Hard Coatings

Physical vapor deposition（PVD）hard coatings play an irreplaceable role in aerospace,marine engineering,and washing tools because of their high hardness,excellent wear resistance and good anti-corrosion properties.With the rapid development of equipment manufacturing industry,the demand for hard coating is more diversified,and the multi-functional integrated PVD hard coating is the direction of future development.Transparent superhydrophobic coatings are a hot research topic for functional coatings because of their special wettable surface and unique optical properties,and the improvement of mechanical properties is the difficult research point for such coatings.Transparent superhydrophobic coating was innovatively prepared by surface microstructure tuning of titanium-based hard coating.It not only provides a new solution to enhance the mechanical properties of transparent hydrophobic coatings,but also provides research ideas for the multi-functionalization of PVD hard coatings.The main research contents and conclusions are as follows:（1）A transparent superhydrophobic coating（F-TNTs/TiN）with self-cleaning properties,mechanical stability,corrosion resistance and durability was prepared by microstructure tuning and functionalization of the TiN coating surface.The TiN coating surface formed a composite structure embedded with Ti O₂ nanotubes,followed by 1H,1H,2H,2H-perfluorodecyltriethoxysilane（PFDS）immersion to reduce the surface energy and achieve superhydrophobicity of the coating.（2）The average transparency of F-TNTs/TiN coating in the visible band can reach 79.6%,and the surface contact angle is increased to 154°.The embedding of nanotubes prevents the growth of TiN columnar crystals and refines the grains,thus the coating exhibits excellent mechanical properties with a hardness of 21.74 GPa.The coating surface shows good durability in the sandpaper linear abrasion test,tape peel test and acid and alkali immersion test.In addition,the special structure of the coating provides three barriers to corrosion protection,and the coating provides excellent protection after 45 days of immersion in corrosive solutions.（3）Ternary TiSiN hard coatings were deposited,and Si-doped transparent superhydrophobic coatings with UV resistance,self-cleaning,mechanical stability and chemical durability were prepared by microstructure tuning and functionalization,which solved the problem that the superhydrophobic properties of the coatings are prone to failure due to UV aging.the Si element doping can make the nanotubes more neat and dense and reduce the surface roughness.（4）The transmittance of F-TNTs/TiSiN coating can reach more than 85%.The special nanotube embedding structure with low surface energy treatment increases the contact angle of the coating to165°,forming a superhydrophobic surface.The addition of Si elements also forms a structure in which the nanocrystals are surrounded by amorphous Si₃N₄,which weakens the UV resistance of the coating due to Ti O₂ photophilic properties,and also enhances the mechanical and chemical durability of the coating,with a good hydrophobic surface after 50 cycles of linear wear of sandpaper.The chemical stability of the coating phase also makes the hydrophobicity of the coating decrease slightly after 24 h of immersion in corrosive solutions,which enables the coating to serve in harsh environments for a long time.