Preparation And Corrosion-wear Properties Of Ti-based Anti-corrosion And Wear-resistant Coatings

Ships and aviation fasteners in the salt spray environment require better friction and wear performance and salt spray corrosion resistance.As a mature method to improve the surface characteristics of materials and improve the performance of materials,coatings have been used in marine aviation and medical fields.It has made great progress.Multi-layer nano-coatings are widely used due to their excellent physical and chemical properties.Among them,the research on Ti-based multi-layer nano-coatings is more in-depth.Testing and analysis of coating failure theories.Use JCP-500 magnetron sputtering equipment to prepare multilayer(9,15,21,30 layers)Ti-based nano-coating(Al/TiN/Ag),and friction test,scratch test,salt spray corrosion experiments,electrochemical experiments and other experimental methods are used to study the comprehensive performance of the coating.SEM,EDS,XRD,and three-dimensional surface profiler were used to collect the comprehensive physical and chemical properties before and after the coating experiment,and comparative analysis.In the friction and wear experiment,a comprehensive comparison of the change law of the friction coefficient of the multilayer nano Al/TiN/Ag coating under different preparation cycles,the change law of the wear depth,and the change law of the wear mechanism were comprehensively compared.In the salt spray corrosion,the changes of salt spray corrosion morphology of different preparation cycles,the changes of the three-dimensional contour of the surface after corrosion,and the changes of elements in the coating after corrosion are comprehensively compared.In the electrochemical experiment,the variation law of the Tafel curve of the multilayer nano-coating under different preparation cycles was comprehensively compared.The experimental results show that,compared with the matrix,the multilayer nano Al/TiN/Ag coating has good wear resistance.The surface morphology of the coating becomes smaller as the preparation cycle increases,and the agglomeration effect decreases;the friction coefficient of the coating increases as the preparation cycle increases,the wear rate gradually decreases,and the abrasive wear of the coating increases.Adhesive wear is reduced,the furrow of the wear interface becomes smaller,and the coating scale is less peeled;with the increase of the preparation cycle of the coating,the change trend of the internal grain of the coating is first to increase and then to decrease.The maximum number of coating layers of the grain is With 21 layers,the coating crystal grain is 50-60nm when the preparation period D?5,and the crystal grain size is 30-40nm when the preparation period is 3D.As the coating preparation cycle increases,the internal internal stress of the coating is well harmonized,but this adjustment method is at the expense of the surface coating\mechanical properties,resulting in positive tensile stress on the surface of the coating after cooling.,This kind of stress mode quickly cracks when the coating is scratched.The main failure modes of the coating under the accelerated salt spray experiment are microscopic crack stress corrosion caused by the internal stress of the coating and pitting corrosion caused by Cl~-enrichment.With the increase of the preparation cycle,the corrosion resistance of the surface layer of the coating increases first and then decreases.Before 5D,the coating played a very good protective role due to its own multilayer mechanical barrier and reaction barrier.After 5D,the coating will increase with the increase of the preparation cycle,and the internal stress will increase due to the increase of the cycle.The difference leads to a further increase in TiN cracks,which in turn leads to aggravation of the surface pitting corrosion of the coating,an increase in the efficiency of corrosion ion entry,and a decrease in the corrosion resistance of the coating.Due to the difference in chemical composition of the coating boundary surface,the probability of galvanic corrosion is increased.Under the condition of macro salt spray corrosion,the corrosion part of the coating is the edge of the coating,which means that the multi-layer coating is complete when the coating is complete.It has good corrosion resistance,but when the coating is cracked,corrosion will occur from the crack and become more serious.The electrochemical experiment table found that as the preparation cycle increases,the coating self-corrosion current(Icorr)decreases,and the electrochemical corrosion performance of the coating becomes more excellent.