Preparation Of MgAl-LDHs Composite Films And Their Corrosion And Wear Resistance

Magnesium alloys have the problems of poor corrosion resistance and wear resistance,and titanium alloys have the problem of poor wear resistance during application.This paper took MgAl-LDHs as the research object,and a variety of composite films were fabricated on the surface of light alloys such as magnesium and titanium.The trivalent metal cation(Ce³⁺)with corrosion inhibition properties,graphene oxide(GO)with good barrier properties and ZrO₂/MoS₂ nanoparticles were introduced into the LDHs laminate structure,the formed MgAlCe-LDHs,MgAl-LDHs@GO and MgAl-LDHs@ZrO₂/MoS₂ composite film layer enhanced corrosion resistance and wear resistance for light alloys.The influence of different corrosion-inhibiting ions and graphene oxide content and other factors on the corrosion resistance of MgAl-LDHs film was systematically studied.By studying the effect of different nanoparticles(ZrO₂/MoS₂)on the friction and wear of MgAl-LDHs film,the friction and wear mechanism model of MgAl-LDHs@ZrO₂/MoS₂ composite film layer was established.In this paper,scanning electron microscope(SEM),X-ray diffraction(XRD),Fourier infrared spectrometer(FT-IR),Raman microscopy(Raman),X-ray photoelectron spectroscopy(XPS)and energy dispersive spectrometry(EDS)were used to characterize different samples.Studies have shown that trivalent metal cations(Ce³⁺),corrosion-inhibiting anions(V₂O₇^4-),graphene oxide and ZrO₂and MoS₂ nanoparticles had been successfully loaded into the LDHs membrane layer.And the electrochemical workstation and tribological tests were used to measure the corrosion resistance and wear resistance of different samples,respectively.The test results showed that the double-doped LDHs composite film(MgAlCe-V₂O₇^4-LDHs)haved greatly improved the corrosion resistance of the magnesium alloy AZ31.The trivalent metal cation(Ce³⁺)and corrosion inhibitor anion(V₂O₇^4-)had a synergistic effect.The MgAlCe-LDHs film layer acted as a good physical barrier,extending the path of chloride ions contacting the substrate,and when corrosion damage occured,the MgAlCe-LDHs film layer could capture Cl^-in the solution and released V₂O₇^4-between the layers,thereby further inhibiting the invasion of the corrosion medium.The corrosion current density of the MgAl-LDHs@GO composite film increased with increasing graphene oxide concentration.A suitable graphene oxide concentration(0.01 g/L)could promote the cross-linking density and increase isolation performance,thus showing good protection performance.MgAl-LDHs@ZrO₂ and MgAl-LDHs@MoS₂ composite film layers remained intact in the tribological tests,and the friction coefficients were reduced to0.21 and 0.26,respectively.ZrO₂ and MoS₂ nanoparticles slightly improved the corrosion resistance of MgAl-LDHs film,and greatly improved their wear resistance.The LDHs coating and nanoparticles had a synergistic effect on the improvement of the wear resistance of Ti10V2Fe3Alalloy.Among them,MgAl-LDHs@ZrO₂ had the best wear resistance.Significant improvement in wear resistance was attributed to rolling effect and the formation of self-lubricating layer.