The wear and corrosion resistance of Fe_（72.2）Cr_（16.8）Ni_（7.3）Mo_（1.6）Mn_（0.7）C_（0.2）Si_（1.2） and Fe_（77.3）Cr_（15.8）Ni_（3.9）Mo_（1.1）Mn_（0.5）C_（0.2）Si_（1.2） coatings laser-cladded on AISI 4...The wear and corrosion resistance of Fe_（72.2）Cr_（16.8）Ni_（7.3）Mo_（1.6）Mn_（0.7）C_（0.2）Si_（1.2） and Fe_（77.3）Cr_（15.8）Ni_（3.9）Mo_（1.1）Mn_（0.5）C_（0.2）Si_（1.2） coatings laser-cladded on AISI 4130 steel were studied.The coatings possess excellent wear and corrosion resistance despite the absence of expensive yttrium,tungsten,and cobalt and very little molybdenum.The microstructure mainly consists of dendrites and eutectic phases,such as duplex（γ＋α）-Fe and the Fe–Cr（Ni）solid solution,confirmed via energy dispersive spectrometry and X-ray diffraction.The cladded Fe-based coatings have lower coefficients of friction,and narrower and shallower wear tracks than the substrate without the cladding,and the main wear mechanism is mild abrasive wear.Electrochemical test results suggest that the soft Fe_（72.2）Cr_（16.8）Ni_（7.3）Mo_（1.6）Mn_（0.7）C_（0.2）Si_（1.2） coating with high Cr and Ni concentrations has high passivation resistance,low corrosion current,and positive corrosion potential,providing a better protective barrier layer to the AISI 4130 steel against corrosion.展开更多
To select the proper composition and obtain an overall material?microstructure?property relationship for Cu?Fe alloy, theeffect of Fe content on microstructure and properties of Cu?Fe-based composite coatings by laser...To select the proper composition and obtain an overall material?microstructure?property relationship for Cu?Fe alloy, theeffect of Fe content on microstructure and properties of Cu?Fe-based composite coatings by laser induction hybrid rapid claddingwas investigated. Microstructure characterization of the composite coatings was tested utilizing SEM, XRD and EDS. Microhardnessmeasurement was executed to evaluate the mechanical properties of the composite coatings. The results show that for low Fe content,the composite coating presents a feature that Fe-rich equiaxed dendrites are embedded in the Cu-rich matrix. With increasing Fecontent, the Fe-rich particles are dispersed in the Cu-rich matrix. With further increasing Fe content, large amounts of Cu-richparticles are homogeneously dispersed in the interdendrite of the Fe-rich matrix. Correspondingly, the average microhardness of thecomposite coatings increases gradually with the increase of Fe content and the microhardness of Cu14.5Fe83Si2C0.5 coating is muchtwice higher than that of the substrate.展开更多
In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) ...In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) spraying.The microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6L stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous phase.Bonding strength of coatings to the substrate was determined by 'pull-off' tensile tests.The results revealed that the31 6L stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous splats.The addition of31 6L stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.展开更多
The Fe-based WC composite coatings were clad on Q235 steel by double-pass plasma cladding method,in which the WC-Co(WC covered with cobalt:78wt%WC,12wt%Co)doping was about 10wt%,20wt%and 40wt%,respectively.The microst...The Fe-based WC composite coatings were clad on Q235 steel by double-pass plasma cladding method,in which the WC-Co(WC covered with cobalt:78wt%WC,12wt%Co)doping was about 10wt%,20wt%and 40wt%,respectively.The microstructure and wear performance of the composite coatings were investigated by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ball-disc wear tests.The results show that the clad coatings contain mainly?-Fe,WC and carbides(Cr23C6,Fe3W3C-Fe4W2C)phases and the precipitation of carbides increases with the increase of WC-Co doping content.The WC-Co doping content has an obvious effect on the microstructure of the clad coatings.For the clad coatings with low WC-Co doping,the microstructure gradually transforms from planar crystal at the interface of substrate/coating to cell/dendritic crystal at the middle and the upper portion of the coatings.But there are a number of fishbone-like structure at the middle and the upper portion of clad coating with 40wt%WC-Co doping.The microstructure at the top is smaller than that at the bottom for all the coatings.The maximum of hardness of the clad coatings is 72.3HRC which is about 6.9 as much as the hardness of Q235 steel substrate.The composite coatings have good wear resistance due to the reinforcement of carbide particles and the strong bonding between carbide particles and ferroalloy.The suitable increase of WC-Co doping content can improve the wear resistance of the composite coatings.展开更多
Fe-based amorphous composite coatings were fabricated on AISI 1045 steel by laser cladding. The results of the X- ray diffraction and transmission electron microscopy analyses .show the coating is composed of an amorp...Fe-based amorphous composite coatings were fabricated on AISI 1045 steel by laser cladding. The results of the X- ray diffraction and transmission electron microscopy analyses .show the coating is composed of an amorphous phase in majority and a nanocrystaUine phuse in m,inority. Phase composition of the coating changes along the depth of the coating. The reasonable scanning speed for fabricating an amorphous composite coating is 3 500 mm/min when the laser power is 4 800 W and the laser beam diameter is 2 mm. If the scanning speed is lower than 3 500 mm/min, the intensity of the two main diffraction peaks in X-ray diffraction patterns of the coatings decreases with the scanning speeds increasing. At the same time, a broad halo peak emerges and enlarges. High laser power and fast scanning speed are the essential conditions of amorphization. The coating exhibits high microhardness.展开更多
Multicomponent(Hf-Zr-Ta)B_(2)potentially provides improved ablation resistance compared with silicon-based ceramics.Here we deposited(Hf_(0.5-x/2)Zr_(0.5-x/2)Ta_(x))B_(2)(x=0,0.1,and 0.2)coatings onto C/C com-posites,...Multicomponent(Hf-Zr-Ta)B_(2)potentially provides improved ablation resistance compared with silicon-based ceramics.Here we deposited(Hf_(0.5-x/2)Zr_(0.5-x/2)Ta_(x))B_(2)(x=0,0.1,and 0.2)coatings onto C/C com-posites,and investigated their ablation behaviors under an oxyacetylene torch with a heat flux of 2.4 MW m^(-2).It was observed that the x=0.1 oxide scale bulged but was denser,and the x=0.2 oxide scale was blown away due to the formation of excessive liquid.Based on these findings,we further de-veloped a duplex(Hf-Zr-Ta)B_(2)coating that showed a linear recession rate close to zero(0.11μm s^(-1))after two 120-s ablation cycles.It is identified that the resulting oxide scale is mainly composed of(Hf,Zr)_(6)Ta_(2)O_(17)and(Hf,Zr,Ta)O_(2)by performing aberration-corrected(scanning)transmission electron microscopy.The protective mechanism is related to the peritectic transformation of orthorhombic-(Hf,Zr)_(6)Ta_(2)O_(17)to tetragonal-(Hf,Zr,Ta)O_(2)plus Ta-dominated liquid.This study contributes to the develop-ment of Ta-containing multicomponent UHTC bulk and coatings for ultra-high temperature applications.展开更多
Mg alloy matrix composites reinforced with short carbon fibers(C_(sf)/Mg)are considered as potential candidates for integrated structural-functional electronic parts that satisfy the requirements of lightweight,excell...Mg alloy matrix composites reinforced with short carbon fibers(C_(sf)/Mg)are considered as potential candidates for integrated structural-functional electronic parts that satisfy the requirements of lightweight,excellent mechanical properties,and heat dissipation.However,the different characteristics of C_(sf)and Mg alloy make the interface a critical issue affecting the synergistic improvement of thermal and mechanical properties of the composites.Here,Cu coating with different thicknesses is introduced to modify the C_(sf)/Mg interface,so as to simultaneously enhance the thermal and mechanical performances,which can combine the advantages of coating modification and matrix alloying.Results reveal that thermal diffusivity(TD)of 3-C_(sf)-Cu/Mg composites is as high as 22.12 mm^(2)/s and an enhancement of 52.97%is achieved compared with C_(sf)/Mg composites,as well as 16.3%enhancement of ultimate compressive strength(UCS)in the longitudinal direction,8.84%improvement of UCS in the transverse direction,and 53.08%increasement of ultimate tensile strength(UTS).Such improvement can be ascribed to the formation of intermetallic compounds.The formation of intermetallic compounds can not only effectively alleviate the lattice distortion of the matrix and decrease interfacial thermal resistance,but also bear the loads.Our work is of great significance for designing C_(sf)/Mg composites with integrated structure and function.展开更多
Superhydrophobicity endows various substrates with astonishing multifunctional properties and has received widespread praise in industrial production.However,the fragile connection between the coating and the substrat...Superhydrophobicity endows various substrates with astonishing multifunctional properties and has received widespread praise in industrial production.However,the fragile connection between the coating and the substrate not only limits the service life of superhydrophobic coatings,but also poses limitations.To address this issue,this study used 3-(perfluorooctyl)propanol and organic polysilazane(OPSZ)with universal anchoring properties as starting materials to obtain fluorine modified OPSZ through a one-step synthesis method,and then doped SiO_(2)micro nano particles to produce superhydrophobic coatings that can be widely applied to various substrates.Investigating the relationship between the hydrophobic properties of the coatings and the amounts of SiO_(2)microparticles and nanoparticles used to create the microscopic rough structure of the superhydrophobic coatings,it was discovered that the hydrophobic properties of the coatings tended to increase as the number of nanoparticles increased.The water contact angle of prepared coatings was still over 157°after 48 h of UV exposure or 180 days of exposure to air.The heat resistance of the created superhydrophobic coatings was tested in a muffle furnace at 400℃ for 2 h.The results revealed that the coatings maintained their water contact angle of 155.1°±3.01°and water sliding angle of 6.4°±1.98°,demonstrating their excellent heat resistance and suitability for use in a variety of high-temperatu re environme nts.The work provided a practical way for creating superhydrophobic composite coatings with excellent mechanical stability,acid and alkali corrosion resistance,and heat resistance,and had potential application in antifouling and anti-corrosion.展开更多
In order to simultaneously improve the oxidation resistance and the electrical conductivity of solid oxide fuel cell(SOFC)interconnectors,a composite coating of Co–W/NiO was fabricated on ferritic stainless steel by ...In order to simultaneously improve the oxidation resistance and the electrical conductivity of solid oxide fuel cell(SOFC)interconnectors,a composite coating of Co–W/NiO was fabricated on ferritic stainless steel by composite deposition and pre-oxidation.Based on phase identification and microstructural analysis,the novel coating was confirmed to effectively suppress Cr diffusion to form a compact Cr-rich layer.Thus,the oxidation rate has been reduced to 9.46×10−15 g^(2)cm^(−4)s^(−1),which showed a imporvement of 56.4%in oxidation resistance.The area specific resistance value of Co–W/NiO coated steel was evaluated as 27.6 mΩcm^(2),much lower than that of Co–W coating as 53.38 mΩcm^(2),which is adequate for SOFC application.Furthermore,the mechanism of the improvement has been investigated that the addition of NiO led to the formation of Ni–Co spinels and Ni–W composites,which affected the surface microstructure of the coating.Thus,the composite Co–W/NiO coated ferritic stainless steel exhibited the optimal combination for oxidation resistance and electrical conductivity.展开更多
This study successfully developed a series of carbon-sol-reinforced copper(Cu-CS)composite coatings by electrodeposition employing a superiorly dispersed carbon sol(CS)to avoid nanoparticle aggregation.The CS,characte...This study successfully developed a series of carbon-sol-reinforced copper(Cu-CS)composite coatings by electrodeposition employing a superiorly dispersed carbon sol(CS)to avoid nanoparticle aggregation.The CS,characterized using transmission electron microscopy and zeta potential analysis,consisted of carbon particles with an approximate diameter of 300 nm uniformly distributed in the electrolytes.The characteristics of the composite coatings were examined via scanning electron microscopy to observe its microstructures,X-ray diffraction to detect its phase constituents,and durability testing to determine the wear and corrosion resistance.Results indicated a significant improvement in coating thickness,density,and uniformity achieved for the Cu-CS composite coating with the addition of 20m L/L CS.Moreover,the Cu-CS composite coating exhibited a low wear volume(1.15×10^(-3)mm^(3)),a high hardness(HV_(0.5)137.1),and a low corrosion rate(0.191 mm/a).The significant contribution of carbon particles to the improvement of coating performance is mainly influenced by two factors,namely,the strengthening and lubricating effects resulting from the incorporated carbon particles.Nevertheless,overdosage of CS can compromise the microstructure of the Cu-CS composite coating,creating defects and undermining its functionality.展开更多
A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic ox...A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic oxidation to enhance its corrosion resistance and self-healing properties.The morphology,chemical composition,structure,and functional properties of the composite coating were investigated by scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),polarization curve,alternating current impedance,and salt immersion test.The experimental results showed that,after immersion in a 3.5 wt%NaCl solution for 12 h,the coating could effectively protect AZ91D from corrosion.When the coating was damaged,the exposed alloy surface would release metal ions in the corrosive environment and react with the corrosion inhibitor 8-hydroxyquinoline to form a Mg(8-HQ)_(2) chelate,exhibiting significant self-healing behavior.The study results demonstrate the broad application prospects of microcapsule technology in the coating field,providing new ideas for the development of efficient anti-corrosion coatings.展开更多
In order to solve the problem of poor electrical conductivity of conventional magnesium alloy MAO coatings and to further enhance the multifunctionality of magnesium alloy coatings,this study examines the enhancement ...In order to solve the problem of poor electrical conductivity of conventional magnesium alloy MAO coatings and to further enhance the multifunctionality of magnesium alloy coatings,this study examines the enhancement of EW75 through the development of composite coatings designed to improve its corrosion resistance,electrical conductivity,hydrophobicity,and antibacterial properties.MAO was employed as a base treatment,followed by application of organic composite coatings containing conductive graphite powder,silver-copper alloy powder,or a combination of both.Coatings were comprehensively characterized to evaluate their microstructure,corrosion resistance,electrical conductivity,hydrophobicity,and mold resistance.Results indicated that composite coatings significantly enhanced corrosion resistance compared to pure MAO coatings,with MAO-AgCu composite coating exhibiting the best performance.Furthermore,coatings demonstrated improved electrical conductivity,with MAO-AgCu coating displaying the lowest surface resistivity.Hydrophobicity was significantly improved in MAO-C-AgCu coating,and all coatings exhibited robust antibacterial effects,particularly against mold growth.This study enhances magnesium alloys’functionality,with potential applications in corrosion protection,electrical properties,and antimicrobial resistance.展开更多
We synthesized tungsten-doped vanadium dioxide(W-VO_(2))particles via a one-step hydrothermal method,followed by their integration with antimony-doped tin oxide(ATO)nanoparticles to formulate a composite coating.Subse...We synthesized tungsten-doped vanadium dioxide(W-VO_(2))particles via a one-step hydrothermal method,followed by their integration with antimony-doped tin oxide(ATO)nanoparticles to formulate a composite coating.Subsequently,the VO_(2)/ATO composite coating was fabricated through a spin-coating process.The impact of varying W-VO_(2) content and coating thickness on the performance of the composite coatings was systematically investigated by employing X-ray diffraction,particle size distribution analysis,spectrometry,and other pertinent test methodologies.Our findings revealed that an escalation in both W-VO_(2) content and coating thickness retained high transmittance in the near-infrared band at lower temperatures.However,as the temperature increased,a notable reduction in transmittance in the near-infrared band was observed,alongside a slight decrease in transmittance within the visible band.Remarkably,when the W-VO_(2) content reached 5%and the coating thickness was 1253 nm,the transmittance of the composite coating surpassed 80%.Furthermore,the heat insulation effect achieved a remarkable 10.0℃increase.Consequently,the synthesized composite coating demonstrates significant potential for smart glass applications,particularly in the realm of heat-insulating glass.展开更多
Metal wear and corrosion require a protective coating with good corrosion and wear resistance.The inorganic adhesive of methyltriethoxysilane modified silica sol(SMP)was first synthesized by the dehydration condensati...Metal wear and corrosion require a protective coating with good corrosion and wear resistance.The inorganic adhesive of methyltriethoxysilane modified silica sol(SMP)was first synthesized by the dehydration condensation of silica sol(S30)with methyltriethoxysilane in propyl alcohol.Then,SMP was used to modify the organic polyurethane(PU)by adjusting the volume ratio.The optimal ratio of the organic–inorganic hybrid adhesive PU-SMP was obtained by measuring its film-forming,mechanical,and corrosion-resistant properties.Then,PU-SMP and zirconia nanoparticles(ZrO_(2))were used as an adhesive and functional filler to prepare the organic–inorganic composite coating of PU-SMP@ZrO_(2)via spraying on various substrates.The fabricated PU-SMP@ZrO_(2)performed superior mechanical strength,good wear performance,and excellent anti-corrosion property.The pencil hardness of the coating PU-SMP@2.5ZrO_(2)is 7H,the wear mass is reduced from 0.7 to 0.2 mg,and the impedance modulus reached 10^(7)Ωcm^(2).The synthesized organic–inorganic hybrid adhesive and its composite coatings provide a promising approach for constructing functional protective coatings on mechanical engineering material.展开更多
In order to enable efficient and cost-effective rehabilitation of surface-worn hydraulic supports,the synthesis and characterization of a novel Ti(N,B)/AISI431 composite coating formed on the surface of 27MnSi steel a...In order to enable efficient and cost-effective rehabilitation of surface-worn hydraulic supports,the synthesis and characterization of a novel Ti(N,B)/AISI431 composite coating formed on the surface of 27MnSi steel are explored via an exothermic in-situ reaction using the ultra-high speed laser cladding(EHLA in German)technique in combination with direct reaction synthesis(DRS).The aim is to mitigate the high residual stress and interfacial stress gradient in the remanufactured AISI431 coating on 27SiMn steel substrate and enhance surface wear resistance.The microstructure,phase composition and interface characteristics are carefully investigated.Much improved wear performance of the composite coating is revealed,mainly attributed to the in-situ formed Ti(N,B)precipitates,refined microstructure,broadened interface zone and reduced residual stress,benefited from the exothermic in-situ Ti(N,B)-reaction.The potential of combining ultra-high speed laser cladding with DRS is demonstrated to create coatings with tailored properties,providing valuable insights for developing advanced wear-resistant materials for industrial applications using EHLA.展开更多
Conventional nanoparticles incorporated into epoxy coatings suffer from poor compatibility and insufficient corrosion improvement,hindering their practical applications.A dual-strategy approach integrating in-situ hos...Conventional nanoparticles incorporated into epoxy coatings suffer from poor compatibility and insufficient corrosion improvement,hindering their practical applications.A dual-strategy approach integrating in-situ host–vip nanoconfinement and surface self-assembly was devised to fabricate 8HQ@ZIF-8/PDA smart nanocontainers.The vip 8-hydroxyquinoline(8HQ)was encapsulated within the zeolitic imidazolate framework-8(ZIF-8)host,leveraging nanoconfinement effects.A bioinspired polydopamine(PDA)layer was then self-assembled on the 8HQ@ZIF-8 surface through dopamine oxidative self-polymerization,resulting in a robust nanocontainer architecture.Density functional theory(DFT)calculations verify that the molecular interactions between the PDA and the ZIF-8 surface was the chemical adsorption.The resultant 8HQ@ZIF-8/PDA retained the rhombic dodecahedral morphology and crystallinity of ZIF-8,demonstrating controlled pH-responsive release behavior.When incorporated into an epoxy(EP)resin matrix on magnesium alloy,the 8HQ@ZIF-8/PDA/EP smart composite coatings exhibited outstanding interfacial compatibility and long-term stability,achieving a low-frequency impedance(|Z|_(n.n1Hz))of 2.49×10^(7)Ωcm^(2),a maximum phase angle of 82.8°,and a breakpoint frequency(f_(b))of 63.34 Hz after 50 days of immersion in a 3.5 wt%NaCl solution.These findings highlight the exceptional self-healing and corrosion-resistant properties of the 8HQ@ZIF-8/PDA/EP smart composite coatings,underscoring its potential for protecting magnesium alloys in aggressive environments.展开更多
This work used the in-situ synthesis of molten-state nitride ceramic phase-reinforced Ni-based alloy coat-ings,aiming to improve the phase-interface bonding through the interdependent co-solidification be-tween molten...This work used the in-situ synthesis of molten-state nitride ceramic phase-reinforced Ni-based alloy coat-ings,aiming to improve the phase-interface bonding through the interdependent co-solidification be-tween molten droplets.The XRD was used to analyze the physical phases of the composite coatings.The microstructure and phase-interface structure were characterized in detail by combining SEM,TEM,HRTEM,FFT,and SAED techniques.Microhardness tester and microforce microhardness tester were em-ployed to measure the surface hardness and elastic modulus of the composite coatings.The fracture be-havior of the composite coatings was characterized by observing the fracture morphology of the coatings using SEM combined with the EDS technique.It was found that the formation mechanisms of inter-facial misfit dislocation assistance,lattice distortion,aggregation of stacking faults,and specific growth orientation between theγ-Ni matrix phase and each ceramic phase in NiCrBSi-TiCrN composite coat-ings improved the lattice matching between the two-phase interface,which resulted in the formation of atomically corresponding coherent lattice relations and stepped interfacial semi-coherent lattice relations,and enhanced the degree of phase-interface bonding.On this basis,the composite coatings with high Cr content further inhibited the expansion of interphase penetration cracks due to the existence of Cr-rich zones at the phase interface,thus exhibiting high fracture toughness.This work provides new opinions on the improvement of phase-interface bonding and composition design of Ni-based composite coatings.展开更多
Integrating different active substances through carriers and fully exerting their synergistic corrosion inhibition ability is an efficient anticor-rosion strategy.Biotemplate(diatomite)was used to integrate polyanilin...Integrating different active substances through carriers and fully exerting their synergistic corrosion inhibition ability is an efficient anticor-rosion strategy.Biotemplate(diatomite)was used to integrate polyaniline and sodium phosphate,an active antisepticfiller(PANI/DM/SP)was prepared in this work.Moreover,activefillers were combined with epoxy resins to prepare high-efficiency anti-corrosion coatings for mag-nesium alloy protection.The stability of the corrosion inhibitor(sodium phosphate)released by the activefiller was analyzed by establishing a mathematical model.Simultaneously,electrochemical impedance spectroscopy tests demonstrate excellent corrosion inhibition properties of activefillers and the impedance modulus of composite coatings was three orders of magnitude higher than that of the EP coating,due to the synergistic effect of each component of the activefiller.In addition,the mechanical properties of the composite coating were significantly improved,with tests showing a 51.31%increase in rub resistance and two grades of adhesion improvement(ASTM standard).The key of this work was to give full play to the slow-release characteristics of diatomite through scientific methods and promote the synergistic anticorrosion effect of sodium phosphate and polyaniline.展开更多
Because of an unfortunate mistake by authors,the Project(5227010679)of Foundation item was wrong.The corrected Project is shown as follows:Project(52271073).
The new energy vehicle body composed of multi-metals requires a synchronous chemical conversion coating to exhibit excellent corrosion resistance.Herein,we prepared a titanium/zirconium/water-based oligomeric epoxy si...The new energy vehicle body composed of multi-metals requires a synchronous chemical conversion coating to exhibit excellent corrosion resistance.Herein,we prepared a titanium/zirconium/water-based oligomeric epoxy silane composite chemical conversion coating on multi-metals,and conducted an investigation into its electrochemical behavior and micro-zone structural characteristics upon immersion in a 3.5%NaCl solution.The electrochemical results combined with characterization results revealed that the corrosion evolution characteristics of the composite coatings could be categorized into three stages of mild corrosion,synergistic protection,and substrate damage.Besides,Si-OH groups interact with Me-OH at the defect on the multi-metal surface to form an organic monolayer coating.This organic monolayer coating,in conjunction with the synergistic inorganic conversion layer comprising Al_(2)O_(3),TiO_(2),2H_(2)O,ZrO_(2),2H_(2)O,effectively cooperates with the corrosion products to hinder the erosion by the corrosive medium and suppresses the progression of the anodic reaction.展开更多
基金financially supported by the Ocean Public Science and Technology Research Fund Projects of China (No. 201405013-3)the Science & Technology Program of Shanghai Maritime University (No. 20130448)+1 种基金the China Postdoctoral Science Foundation (No. 2017M620153)the National Natural Science Foundation of China (No. 51609133)
文摘The wear and corrosion resistance of Fe_（72.2）Cr_（16.8）Ni_（7.3）Mo_（1.6）Mn_（0.7）C_（0.2）Si_（1.2） and Fe_（77.3）Cr_（15.8）Ni_（3.9）Mo_（1.1）Mn_（0.5）C_（0.2）Si_（1.2） coatings laser-cladded on AISI 4130 steel were studied.The coatings possess excellent wear and corrosion resistance despite the absence of expensive yttrium,tungsten,and cobalt and very little molybdenum.The microstructure mainly consists of dendrites and eutectic phases,such as duplex（γ＋α）-Fe and the Fe–Cr（Ni）solid solution,confirmed via energy dispersive spectrometry and X-ray diffraction.The cladded Fe-based coatings have lower coefficients of friction,and narrower and shallower wear tracks than the substrate without the cladding,and the main wear mechanism is mild abrasive wear.Electrochemical test results suggest that the soft Fe_（72.2）Cr_（16.8）Ni_（7.3）Mo_（1.6）Mn_（0.7）C_（0.2）Si_（1.2） coating with high Cr and Ni concentrations has high passivation resistance,low corrosion current,and positive corrosion potential,providing a better protective barrier layer to the AISI 4130 steel against corrosion.
基金Projects(51471084,61475117)supported by the National Natural Science Foundation of ChinaProject(13ZCZDGX01109)supported by Tianjin Municipal Science and Technology Commission of ChinaProject(20122BBE500031)supported by the Key Technology Project of Jiangxi Province in China
文摘To select the proper composition and obtain an overall material?microstructure?property relationship for Cu?Fe alloy, theeffect of Fe content on microstructure and properties of Cu?Fe-based composite coatings by laser induction hybrid rapid claddingwas investigated. Microstructure characterization of the composite coatings was tested utilizing SEM, XRD and EDS. Microhardnessmeasurement was executed to evaluate the mechanical properties of the composite coatings. The results show that for low Fe content,the composite coating presents a feature that Fe-rich equiaxed dendrites are embedded in the Cu-rich matrix. With increasing Fecontent, the Fe-rich particles are dispersed in the Cu-rich matrix. With further increasing Fe content, large amounts of Cu-richparticles are homogeneously dispersed in the interdendrite of the Fe-rich matrix. Correspondingly, the average microhardness of thecomposite coatings increases gradually with the increase of Fe content and the microhardness of Cu14.5Fe83Si2C0.5 coating is muchtwice higher than that of the substrate.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51271081 and 51301072)partially supported by the Key Fundamental Research Project from Shenzhen Research Council (No. JC201105170745A)
文摘In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) spraying.The microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6L stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous phase.Bonding strength of coatings to the substrate was determined by 'pull-off' tensile tests.The results revealed that the31 6L stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous splats.The addition of31 6L stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.
基金Fundamental Research Funds for the Central Universities(2009B16214)China Postdoctoral Science Foundation funded project(20100481079)Scientific Research Start-up Fund Project of Hohai University(20080403)
文摘The Fe-based WC composite coatings were clad on Q235 steel by double-pass plasma cladding method,in which the WC-Co(WC covered with cobalt:78wt%WC,12wt%Co)doping was about 10wt%,20wt%and 40wt%,respectively.The microstructure and wear performance of the composite coatings were investigated by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ball-disc wear tests.The results show that the clad coatings contain mainly?-Fe,WC and carbides(Cr23C6,Fe3W3C-Fe4W2C)phases and the precipitation of carbides increases with the increase of WC-Co doping content.The WC-Co doping content has an obvious effect on the microstructure of the clad coatings.For the clad coatings with low WC-Co doping,the microstructure gradually transforms from planar crystal at the interface of substrate/coating to cell/dendritic crystal at the middle and the upper portion of the coatings.But there are a number of fishbone-like structure at the middle and the upper portion of clad coating with 40wt%WC-Co doping.The microstructure at the top is smaller than that at the bottom for all the coatings.The maximum of hardness of the clad coatings is 72.3HRC which is about 6.9 as much as the hardness of Q235 steel substrate.The composite coatings have good wear resistance due to the reinforcement of carbide particles and the strong bonding between carbide particles and ferroalloy.The suitable increase of WC-Co doping content can improve the wear resistance of the composite coatings.
文摘Fe-based amorphous composite coatings were fabricated on AISI 1045 steel by laser cladding. The results of the X- ray diffraction and transmission electron microscopy analyses .show the coating is composed of an amorphous phase in majority and a nanocrystaUine phuse in m,inority. Phase composition of the coating changes along the depth of the coating. The reasonable scanning speed for fabricating an amorphous composite coating is 3 500 mm/min when the laser power is 4 800 W and the laser beam diameter is 2 mm. If the scanning speed is lower than 3 500 mm/min, the intensity of the two main diffraction peaks in X-ray diffraction patterns of the coatings decreases with the scanning speeds increasing. At the same time, a broad halo peak emerges and enlarges. High laser power and fast scanning speed are the essential conditions of amorphization. The coating exhibits high microhardness.
基金supported by the National Key R&D Pro-gram of China(Grant No.2021YFA0715803)the National Natural Science Foundation of China(Grant Nos.52293373,52130205,and 52302091)+1 种基金the Joint Fund of Henan Province Science and Technol-ogy R&D Program(No.225200810002)the ND Basic Research Funds of Northwestern Polytechnical University(No.G2022WD).
文摘Multicomponent(Hf-Zr-Ta)B_(2)potentially provides improved ablation resistance compared with silicon-based ceramics.Here we deposited(Hf_(0.5-x/2)Zr_(0.5-x/2)Ta_(x))B_(2)(x=0,0.1,and 0.2)coatings onto C/C com-posites,and investigated their ablation behaviors under an oxyacetylene torch with a heat flux of 2.4 MW m^(-2).It was observed that the x=0.1 oxide scale bulged but was denser,and the x=0.2 oxide scale was blown away due to the formation of excessive liquid.Based on these findings,we further de-veloped a duplex(Hf-Zr-Ta)B_(2)coating that showed a linear recession rate close to zero(0.11μm s^(-1))after two 120-s ablation cycles.It is identified that the resulting oxide scale is mainly composed of(Hf,Zr)_(6)Ta_(2)O_(17)and(Hf,Zr,Ta)O_(2)by performing aberration-corrected(scanning)transmission electron microscopy.The protective mechanism is related to the peritectic transformation of orthorhombic-(Hf,Zr)_(6)Ta_(2)O_(17)to tetragonal-(Hf,Zr,Ta)O_(2)plus Ta-dominated liquid.This study contributes to the develop-ment of Ta-containing multicomponent UHTC bulk and coatings for ultra-high temperature applications.
基金supported by the National Natural Science Foundation of China(grant no.52231004 and 52072305).
文摘Mg alloy matrix composites reinforced with short carbon fibers(C_(sf)/Mg)are considered as potential candidates for integrated structural-functional electronic parts that satisfy the requirements of lightweight,excellent mechanical properties,and heat dissipation.However,the different characteristics of C_(sf)and Mg alloy make the interface a critical issue affecting the synergistic improvement of thermal and mechanical properties of the composites.Here,Cu coating with different thicknesses is introduced to modify the C_(sf)/Mg interface,so as to simultaneously enhance the thermal and mechanical performances,which can combine the advantages of coating modification and matrix alloying.Results reveal that thermal diffusivity(TD)of 3-C_(sf)-Cu/Mg composites is as high as 22.12 mm^(2)/s and an enhancement of 52.97%is achieved compared with C_(sf)/Mg composites,as well as 16.3%enhancement of ultimate compressive strength(UCS)in the longitudinal direction,8.84%improvement of UCS in the transverse direction,and 53.08%increasement of ultimate tensile strength(UTS).Such improvement can be ascribed to the formation of intermetallic compounds.The formation of intermetallic compounds can not only effectively alleviate the lattice distortion of the matrix and decrease interfacial thermal resistance,but also bear the loads.Our work is of great significance for designing C_(sf)/Mg composites with integrated structure and function.
基金supported by the National Key Research and Development Program of China(2022YFC3004901-3)the National Natural Science Foundation of China(21908109)+2 种基金the Open Project of Key Laboratory of Fire Emergency Rescue Equipment of Ministry of Emergency Management of People's Republic of China(2020XFZB05)the Fundamental Research Funds for the Central Universities(30919011272)the Natural Science Foundation of Jiangsu Province(BK20180816)。
文摘Superhydrophobicity endows various substrates with astonishing multifunctional properties and has received widespread praise in industrial production.However,the fragile connection between the coating and the substrate not only limits the service life of superhydrophobic coatings,but also poses limitations.To address this issue,this study used 3-(perfluorooctyl)propanol and organic polysilazane(OPSZ)with universal anchoring properties as starting materials to obtain fluorine modified OPSZ through a one-step synthesis method,and then doped SiO_(2)micro nano particles to produce superhydrophobic coatings that can be widely applied to various substrates.Investigating the relationship between the hydrophobic properties of the coatings and the amounts of SiO_(2)microparticles and nanoparticles used to create the microscopic rough structure of the superhydrophobic coatings,it was discovered that the hydrophobic properties of the coatings tended to increase as the number of nanoparticles increased.The water contact angle of prepared coatings was still over 157°after 48 h of UV exposure or 180 days of exposure to air.The heat resistance of the created superhydrophobic coatings was tested in a muffle furnace at 400℃ for 2 h.The results revealed that the coatings maintained their water contact angle of 155.1°±3.01°and water sliding angle of 6.4°±1.98°,demonstrating their excellent heat resistance and suitability for use in a variety of high-temperatu re environme nts.The work provided a practical way for creating superhydrophobic composite coatings with excellent mechanical stability,acid and alkali corrosion resistance,and heat resistance,and had potential application in antifouling and anti-corrosion.
基金supported by Hubei Natural Science Foundation of Hubei(2023AFB111).
文摘In order to simultaneously improve the oxidation resistance and the electrical conductivity of solid oxide fuel cell(SOFC)interconnectors,a composite coating of Co–W/NiO was fabricated on ferritic stainless steel by composite deposition and pre-oxidation.Based on phase identification and microstructural analysis,the novel coating was confirmed to effectively suppress Cr diffusion to form a compact Cr-rich layer.Thus,the oxidation rate has been reduced to 9.46×10−15 g^(2)cm^(−4)s^(−1),which showed a imporvement of 56.4%in oxidation resistance.The area specific resistance value of Co–W/NiO coated steel was evaluated as 27.6 mΩcm^(2),much lower than that of Co–W coating as 53.38 mΩcm^(2),which is adequate for SOFC application.Furthermore,the mechanism of the improvement has been investigated that the addition of NiO led to the formation of Ni–Co spinels and Ni–W composites,which affected the surface microstructure of the coating.Thus,the composite Co–W/NiO coated ferritic stainless steel exhibited the optimal combination for oxidation resistance and electrical conductivity.
基金financially supported by the Jiangsu Provincial Outstanding Overseas Talent Project,China(No.BX2023029)the Jiangsu Provincial Natural Science Fund Research Project,China(No.BK20211344)+2 种基金the Project of Jiangsu Provincial Department of Science and Technology,Chinathe Jiangsu Provincial Postgraduate Research&Practice Innovation Program,China(No.KYCX22_3795)the Jiangsu Provincial Postgraduate Research&Practice Innovation Program,China(No.SJCX23_2171)。
文摘This study successfully developed a series of carbon-sol-reinforced copper(Cu-CS)composite coatings by electrodeposition employing a superiorly dispersed carbon sol(CS)to avoid nanoparticle aggregation.The CS,characterized using transmission electron microscopy and zeta potential analysis,consisted of carbon particles with an approximate diameter of 300 nm uniformly distributed in the electrolytes.The characteristics of the composite coatings were examined via scanning electron microscopy to observe its microstructures,X-ray diffraction to detect its phase constituents,and durability testing to determine the wear and corrosion resistance.Results indicated a significant improvement in coating thickness,density,and uniformity achieved for the Cu-CS composite coating with the addition of 20m L/L CS.Moreover,the Cu-CS composite coating exhibited a low wear volume(1.15×10^(-3)mm^(3)),a high hardness(HV_(0.5)137.1),and a low corrosion rate(0.191 mm/a).The significant contribution of carbon particles to the improvement of coating performance is mainly influenced by two factors,namely,the strengthening and lubricating effects resulting from the incorporated carbon particles.Nevertheless,overdosage of CS can compromise the microstructure of the Cu-CS composite coating,creating defects and undermining its functionality.
基金Funded by the National Natural Science Foundation of China(No.52271066)Basic Research and Innovation Project for Vehicle Power+1 种基金Key Project of"Two-Chain Integration"in Shaanxi Province(No.2023-LL-QY-33-3)Xi'an Key Laboratory of Corrosion Protection and Functional Coating Technology for Military and Civil Light Alloy and Key Project of Shaanxi Natural Science Foundation Research Program(No.2021JZ-54)。
文摘A novel type of microcapsule-encapsulated corrosion inhibitor was prepared in a water-based solution with a pH range of 7-8,and it was applied to the composite organic coating of magnesium alloy plasma electrolytic oxidation to enhance its corrosion resistance and self-healing properties.The morphology,chemical composition,structure,and functional properties of the composite coating were investigated by scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared spectroscopy(FTIR),polarization curve,alternating current impedance,and salt immersion test.The experimental results showed that,after immersion in a 3.5 wt%NaCl solution for 12 h,the coating could effectively protect AZ91D from corrosion.When the coating was damaged,the exposed alloy surface would release metal ions in the corrosive environment and react with the corrosion inhibitor 8-hydroxyquinoline to form a Mg(8-HQ)_(2) chelate,exhibiting significant self-healing behavior.The study results demonstrate the broad application prospects of microcapsule technology in the coating field,providing new ideas for the development of efficient anti-corrosion coatings.
基金supported by Natural Science Foundation of Shandong Province(ZR2024ME163)Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(No.2021CXLH0005)Wenhai Program of the S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(No.2021WHZZB2301).
文摘In order to solve the problem of poor electrical conductivity of conventional magnesium alloy MAO coatings and to further enhance the multifunctionality of magnesium alloy coatings,this study examines the enhancement of EW75 through the development of composite coatings designed to improve its corrosion resistance,electrical conductivity,hydrophobicity,and antibacterial properties.MAO was employed as a base treatment,followed by application of organic composite coatings containing conductive graphite powder,silver-copper alloy powder,or a combination of both.Coatings were comprehensively characterized to evaluate their microstructure,corrosion resistance,electrical conductivity,hydrophobicity,and mold resistance.Results indicated that composite coatings significantly enhanced corrosion resistance compared to pure MAO coatings,with MAO-AgCu composite coating exhibiting the best performance.Furthermore,coatings demonstrated improved electrical conductivity,with MAO-AgCu coating displaying the lowest surface resistivity.Hydrophobicity was significantly improved in MAO-C-AgCu coating,and all coatings exhibited robust antibacterial effects,particularly against mold growth.This study enhances magnesium alloys’functionality,with potential applications in corrosion protection,electrical properties,and antimicrobial resistance.
基金Funded by Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park(No.Z221100006722022)。
文摘We synthesized tungsten-doped vanadium dioxide(W-VO_(2))particles via a one-step hydrothermal method,followed by their integration with antimony-doped tin oxide(ATO)nanoparticles to formulate a composite coating.Subsequently,the VO_(2)/ATO composite coating was fabricated through a spin-coating process.The impact of varying W-VO_(2) content and coating thickness on the performance of the composite coatings was systematically investigated by employing X-ray diffraction,particle size distribution analysis,spectrometry,and other pertinent test methodologies.Our findings revealed that an escalation in both W-VO_(2) content and coating thickness retained high transmittance in the near-infrared band at lower temperatures.However,as the temperature increased,a notable reduction in transmittance in the near-infrared band was observed,alongside a slight decrease in transmittance within the visible band.Remarkably,when the W-VO_(2) content reached 5%and the coating thickness was 1253 nm,the transmittance of the composite coating surpassed 80%.Furthermore,the heat insulation effect achieved a remarkable 10.0℃increase.Consequently,the synthesized composite coating demonstrates significant potential for smart glass applications,particularly in the realm of heat-insulating glass.
基金supported by National Key R&D Project of China(No.2024YFB4600167)the National Natural Science Foundation of China(No.52205313)+1 种基金Natural Science Foundation of Shandong Province(Nos.ZR2022ZD07 and ZR2022QE161)China Postdoctoral Science Foundation(No.2023M734093).
文摘Metal wear and corrosion require a protective coating with good corrosion and wear resistance.The inorganic adhesive of methyltriethoxysilane modified silica sol(SMP)was first synthesized by the dehydration condensation of silica sol(S30)with methyltriethoxysilane in propyl alcohol.Then,SMP was used to modify the organic polyurethane(PU)by adjusting the volume ratio.The optimal ratio of the organic–inorganic hybrid adhesive PU-SMP was obtained by measuring its film-forming,mechanical,and corrosion-resistant properties.Then,PU-SMP and zirconia nanoparticles(ZrO_(2))were used as an adhesive and functional filler to prepare the organic–inorganic composite coating of PU-SMP@ZrO_(2)via spraying on various substrates.The fabricated PU-SMP@ZrO_(2)performed superior mechanical strength,good wear performance,and excellent anti-corrosion property.The pencil hardness of the coating PU-SMP@2.5ZrO_(2)is 7H,the wear mass is reduced from 0.7 to 0.2 mg,and the impedance modulus reached 10^(7)Ωcm^(2).The synthesized organic–inorganic hybrid adhesive and its composite coatings provide a promising approach for constructing functional protective coatings on mechanical engineering material.
基金financially supported by the National Key Research and Development Program of China(No.2023YFB4606200)Technical Development Foundation of China Academy of Machinery Science and Technology Group(No.812201Q9)+2 种基金Fundamental Research Funds of National Institute of Metrology of China(No.AKYRC2401)Beijing Natural Science Foundation(No.2222093)the National Key Research and Development Program of China(No.2021YFB3702003)。
文摘In order to enable efficient and cost-effective rehabilitation of surface-worn hydraulic supports,the synthesis and characterization of a novel Ti(N,B)/AISI431 composite coating formed on the surface of 27MnSi steel are explored via an exothermic in-situ reaction using the ultra-high speed laser cladding(EHLA in German)technique in combination with direct reaction synthesis(DRS).The aim is to mitigate the high residual stress and interfacial stress gradient in the remanufactured AISI431 coating on 27SiMn steel substrate and enhance surface wear resistance.The microstructure,phase composition and interface characteristics are carefully investigated.Much improved wear performance of the composite coating is revealed,mainly attributed to the in-situ formed Ti(N,B)precipitates,refined microstructure,broadened interface zone and reduced residual stress,benefited from the exothermic in-situ Ti(N,B)-reaction.The potential of combining ultra-high speed laser cladding with DRS is demonstrated to create coatings with tailored properties,providing valuable insights for developing advanced wear-resistant materials for industrial applications using EHLA.
基金the Natural Science Foundation of Hunan Province(2024JJ6364)the National Natural Science Foundation of China(52271073)+1 种基金the Sichuan Science and Technology Program(2024NSFJQ0034)the Innovation Team Funds of China West Normal University(KCXTD2024-1).
文摘Conventional nanoparticles incorporated into epoxy coatings suffer from poor compatibility and insufficient corrosion improvement,hindering their practical applications.A dual-strategy approach integrating in-situ host–vip nanoconfinement and surface self-assembly was devised to fabricate 8HQ@ZIF-8/PDA smart nanocontainers.The vip 8-hydroxyquinoline(8HQ)was encapsulated within the zeolitic imidazolate framework-8(ZIF-8)host,leveraging nanoconfinement effects.A bioinspired polydopamine(PDA)layer was then self-assembled on the 8HQ@ZIF-8 surface through dopamine oxidative self-polymerization,resulting in a robust nanocontainer architecture.Density functional theory(DFT)calculations verify that the molecular interactions between the PDA and the ZIF-8 surface was the chemical adsorption.The resultant 8HQ@ZIF-8/PDA retained the rhombic dodecahedral morphology and crystallinity of ZIF-8,demonstrating controlled pH-responsive release behavior.When incorporated into an epoxy(EP)resin matrix on magnesium alloy,the 8HQ@ZIF-8/PDA/EP smart composite coatings exhibited outstanding interfacial compatibility and long-term stability,achieving a low-frequency impedance(|Z|_(n.n1Hz))of 2.49×10^(7)Ωcm^(2),a maximum phase angle of 82.8°,and a breakpoint frequency(f_(b))of 63.34 Hz after 50 days of immersion in a 3.5 wt%NaCl solution.These findings highlight the exceptional self-healing and corrosion-resistant properties of the 8HQ@ZIF-8/PDA/EP smart composite coatings,underscoring its potential for protecting magnesium alloys in aggressive environments.
基金supported by the National Natural Science Foundation of China(No.52271055)the Natural Science Foundation of Hebei Province(No.E2021202130).
文摘This work used the in-situ synthesis of molten-state nitride ceramic phase-reinforced Ni-based alloy coat-ings,aiming to improve the phase-interface bonding through the interdependent co-solidification be-tween molten droplets.The XRD was used to analyze the physical phases of the composite coatings.The microstructure and phase-interface structure were characterized in detail by combining SEM,TEM,HRTEM,FFT,and SAED techniques.Microhardness tester and microforce microhardness tester were em-ployed to measure the surface hardness and elastic modulus of the composite coatings.The fracture be-havior of the composite coatings was characterized by observing the fracture morphology of the coatings using SEM combined with the EDS technique.It was found that the formation mechanisms of inter-facial misfit dislocation assistance,lattice distortion,aggregation of stacking faults,and specific growth orientation between theγ-Ni matrix phase and each ceramic phase in NiCrBSi-TiCrN composite coat-ings improved the lattice matching between the two-phase interface,which resulted in the formation of atomically corresponding coherent lattice relations and stepped interfacial semi-coherent lattice relations,and enhanced the degree of phase-interface bonding.On this basis,the composite coatings with high Cr content further inhibited the expansion of interphase penetration cracks due to the existence of Cr-rich zones at the phase interface,thus exhibiting high fracture toughness.This work provides new opinions on the improvement of phase-interface bonding and composition design of Ni-based composite coatings.
基金support provided by the National Natural Science Foundation of China(Grant No.51908092)Projects(No.2020CDJXZ001,2021CDJJMRH-005 and SKLMT-ZZKT-2021M04)supported by the Fundamental Research Funds for the Central Universities+6 种基金the Joint Funds of the National Natural Science Foundation of China-Guangdong(Grant No.U1801254)the project funded by Chongqing Special Postdoctoral Science Foundation(XmT2018043)the Chongqing Research Program of Basic Research and Frontier Technology(cstc2017jcyjBX0080)Natural Science Foundation Project of Chongqing for Post-doctor(cstc2019jcyjbsh0079,cstc2019jcyjbshX0085)Technological projects of Chongqing Municipal Education Commission(KJZDK201800801)the Innovative Research Team of Chongqing(CXTDG201602014)the Innovative technology of New materials and metallurgy(2019CDXYCL0031)。
文摘Integrating different active substances through carriers and fully exerting their synergistic corrosion inhibition ability is an efficient anticor-rosion strategy.Biotemplate(diatomite)was used to integrate polyaniline and sodium phosphate,an active antisepticfiller(PANI/DM/SP)was prepared in this work.Moreover,activefillers were combined with epoxy resins to prepare high-efficiency anti-corrosion coatings for mag-nesium alloy protection.The stability of the corrosion inhibitor(sodium phosphate)released by the activefiller was analyzed by establishing a mathematical model.Simultaneously,electrochemical impedance spectroscopy tests demonstrate excellent corrosion inhibition properties of activefillers and the impedance modulus of composite coatings was three orders of magnitude higher than that of the EP coating,due to the synergistic effect of each component of the activefiller.In addition,the mechanical properties of the composite coating were significantly improved,with tests showing a 51.31%increase in rub resistance and two grades of adhesion improvement(ASTM standard).The key of this work was to give full play to the slow-release characteristics of diatomite through scientific methods and promote the synergistic anticorrosion effect of sodium phosphate and polyaniline.
文摘Because of an unfortunate mistake by authors,the Project(5227010679)of Foundation item was wrong.The corrected Project is shown as follows:Project(52271073).
基金financially supported by the National Natural Science Foundation of China(No.52075391).
文摘The new energy vehicle body composed of multi-metals requires a synchronous chemical conversion coating to exhibit excellent corrosion resistance.Herein,we prepared a titanium/zirconium/water-based oligomeric epoxy silane composite chemical conversion coating on multi-metals,and conducted an investigation into its electrochemical behavior and micro-zone structural characteristics upon immersion in a 3.5%NaCl solution.The electrochemical results combined with characterization results revealed that the corrosion evolution characteristics of the composite coatings could be categorized into three stages of mild corrosion,synergistic protection,and substrate damage.Besides,Si-OH groups interact with Me-OH at the defect on the multi-metal surface to form an organic monolayer coating.This organic monolayer coating,in conjunction with the synergistic inorganic conversion layer comprising Al_(2)O_(3),TiO_(2),2H_(2)O,ZrO_(2),2H_(2)O,effectively cooperates with the corrosion products to hinder the erosion by the corrosive medium and suppresses the progression of the anodic reaction.
