Preparation And Research Of Brass Molybdate/nanoparticle Doped Silane Composite Passivation Film

As one of the most demanding alloys in the modern industry,brass is widely used for its beautiful appearance,excellent corrosion resistance and excellent mechanical properties.China as the largest producer and consumer of brass,Brass tubes,brass rods and wires are already in the world’s leading stage.At present,brass has been applied to ship propellers,air conditioning condensers,medical intrauterine devices,and various processing components.Corrosion protection as an important research topic in the field of brass application,how to develop high corrosion resistance,green and environmentally friendly brass surface passivation technology to replace the traditional high pollution chromate passivation technology has become an important application in brass industrial applicationchallenge.In this experiment,H62 brass was used as the matrix.Firstly,a molybdate complex benzotriazole(BTA)passivation film was prepared on the surface of the brass substrate.The molybdate concentration was studied by orthogonal experiment and single factor method.The concentration of benzotriazole,the concentration of sulfosalicylic acid,the reaction time and the reaction temperature are preferred forthe primary and secondary conditions of the coating;in order to further improve thecorrosion resistance and adhesion of the brass passivation film The experiment also selected threekindsof silane couplingagents underdifferent hydrolysisconditions,γ-aminopropyltrimethoxysilane(KH540),γ-aminopropyltriethoxy silane(KH550),and γ-mercaptopropyltrimethyl Theoxysilane(KH-590)-doped nanoparticles Finally,the molybdate compounded BTA/nanoparticle doped silane was prepared by a two-step method.Large composite film layer,and the overall film resistance,adhesion and hydrophobicity were measured.The experimental results show that the large composite film layer prepared under this new process has excellent corrosion resistance,the corrosion potential is increased by 123mV,and the corrosion current density is decreased.The passivated brass sample is resistant to corrosion for more than 96 hours in a neutral salt spray box.The adhesion test showed that the bonding strength of the large composite film layer was good,up to 4.9 MPa,and the wettability test showed that the film layer had excellent hydrophobic properties.The passivation technology is a green,environmentally friendly new process and is a promising alternative to the traditional chromate process.