Preparation And Tribological Properties Of Ni-GO/Al₂O₃ Composite Coatings

Composite coatings are widely used in aerospace,electronic information,chemical manufacturing and other engineering technology because they have the characteristics of matrix metal and coated particles,which can improve the mechanical properties and friction properties of the matrix and prolong the service life.The continuous development of science and technology and the deepening of human exploration of the world have made the application environment of materials more and more complex,and the requirements for material properties have also increased accordingly.The surface function of the material can be improved by the composite plating technique,but the excellent performance depends largely on the properties of the coating particles.The use of high-performance materials as composite coating particles on the one hand improves the mechanical properties of the coating and on the other hand improves the friction and wear characteristics of the surface.In this paper,a composite electro-deposition method was used to prepare nickel-based composite coatings with fine graphene oxide?GO?and GO/Al₂O₃ powder solids as particles,and the performance changes were verified by experiments.The research contents and main conclusions of this paper are as follows:1.Using nano-graphite powder as raw material,GO particles were synthesized by modified Hummers method;then GO and Al₂O₃ powders were obtained,and GO/Al₂O₃ composites were obtained by hydrothermal reaction.The above two powders were characterized by XRD,FT-IR,SEM,TEM and other characterization methods,and applied to the composite coating.2.By changing the concentration of GO in the plating solution,the effect of the amount of particulate added on the performance of the composite coating was investigated.The experimental results show that the hardness and friction and wear characteristics of Ni/GO coatings are greatly improved compared with pure Ni coatings under the same plating conditions,and the coating properties are also improved with the increase of GO content..However,the composite coating exhibits the best performance only when the GO content in the bath is within a certain range.Changes in current density and plating time can also have a large impact on the improvement of coating properties.3.Change the initial ratio of Al₂O₃ and GO in the configuration of GO/Al₂O₃ composites,and study the properties of coatings obtained with different proportions of GO/Al₂O₃ as particles.The results show that when the mass ratio of Al₂O₃ increases,the hardness of the coating increases gradually,the friction coefficient decreases,and the wear rate decreases.When at the same ratio,the increase in particle concentration,plating time,and current density enhances the wear resistance of the coating.