Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited on to a steel substrate by the successive deposition of zinc and Zn-Ni alloy sublayers from dual baths. The coated sampl...Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited on to a steel substrate by the successive deposition of zinc and Zn-Ni alloy sublayers from dual baths. The coated samples were evaluated in terms of the surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The microstructural characteristics that were examined using the field emission gun scanning electron microscopy （FEGSEM） confirmed the layered structure, grain refinement of the zinc and Zn-Ni alloy CMM coatings, and revealed the existence of microcracks caused by the internal stress in the thick Zn-Ni alloy sublayers. The corrosion resistance that was evaluated by means of the salt spray test shows that the zinc and Zn-Ni alloy CMM coatings were more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy of the same thickness. The possible reasons for the better protective performance of Zn-Ni/Zn CMM coatings were given on the basis of the analysis on the micrographic features of zinc and Zn-Ni alloy CMM eoatings after the corrosion test. A probable corrosion mechanism of zinc and Zn-Ni alloy CMM coatings was also proposed.展开更多
Polycrystalline Cr2AlC coatings were prepared on M38G superalloy using a two-step method consisting of magnetron sputtering from Cr-Al-C composite targets at room temperature and subsequent annealing at 620 ℃. Partic...Polycrystalline Cr2AlC coatings were prepared on M38G superalloy using a two-step method consisting of magnetron sputtering from Cr-Al-C composite targets at room temperature and subsequent annealing at 620 ℃. Particularly, various targets synthesized by hot pressing mixture of Cr, Al, and C powders at 650-1000 ℃ were used. It was found that regardless of the phase compositions and density of the com- posite targets, when the molar ratio of Cr：Al：C in the starting materials was 2：1：1, phase-pure crystalline Cr2AlC coatings were prepared by magnetron sputtering and post crystallization. The Cr2AIC coatings were dense and crack-free and had a duplex structure. The adhesion strength of the coating deposited on M38G superalloy from the 800 ℃ hot-pressed target and then annealed at 620 ℃ for 20 h in Ar exceeded 82 ± 6 MPa, while its hardness was 12 ± 3 GPa.展开更多
Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited from dual baths. The coated samples were evaluated in terms of surface appearance, surface and cross-sectional morpholog...Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited from dual baths. The coated samples were evaluated in terms of surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The results obtained from the salt spray test show that the zinc and Zn-Ni alloy CMM coatings are more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy alone with a similar thickness. The corrosion potential measurement and anodic polarisation tests were undertaken to examine the probable corrosion mechanisms of zinc and Zn-Ni alloy CMM coatings. Analysis on the micrographic features of zinc and Zn-Ni alloy CMM coatings after the corrosion test explains the probable reasons why the Zn-Ni/Zn CMM coatings have a better protective performance. Surface morphologies and compositional analysis of the remaining coating material of Zn-Ni alloy deposit after the corrosion test confirms the dezincification mechanism of the Zn-Ni alloy deposit during the corrosion process.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
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
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
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
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
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
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
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
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
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 corrosion behavior of Ni-Co-CeO_(2) composite coating was investigated under a simulated high-temperature marine atmosphere alongside Ni-Co coating. The corrosion kinetics, phase composition and microstructure evo...The corrosion behavior of Ni-Co-CeO_(2) composite coating was investigated under a simulated high-temperature marine atmosphere alongside Ni-Co coating. The corrosion kinetics, phase composition and microstructure evolution of the coatings were analyzed. A multi-layered oxide scale formed due to the synergistic corrosion by H_(2)O and NaCl. The growth mechanism of the Co_(3)O_(4), Fe_(3)O_(4), Fe_(2)O3, CoFe_(2)O_(4), NiFe_(2)O_(4) and NiO in the scale was proposed according to the distribution of the CeO_(2) particles. Compared to Ni-Co cating, the Ni-Co-CeO_(2) coating exhibited superior corrosion resistance in the H_(2)O/NaCl steam, which is beacause the CeO_(2) exerted a blocking effect on retarding the diffusion of Fe atoms and corrosive medium, contributing to a reduced corrosion rate and an improved oxide adhesion compared to Ni-Co coating.展开更多
Combining Mg and Al dissimilar metals further reduces structural weight,but the formation of intermetallic compounds(IMCs)affectsAl/Mg joint properties.To prevent IMCs,a Ni-Al_(2)O_(3)composite coating was pre-plated ...Combining Mg and Al dissimilar metals further reduces structural weight,but the formation of intermetallic compounds(IMCs)affectsAl/Mg joint properties.To prevent IMCs,a Ni-Al_(2)O_(3)composite coating was pre-plated on the Mg alloy substrate,and then Sn_(3.0)Ag_(0.5)Cu(SAC 305)solder was utilized to facilitate the joining of AZ31 Mg/6061 Al through ultrasonic-assisted soldering.We investigated the impactof Al_(2)O_(3)nano sol content in the coating on microstructure evolution,IMCs formation,and mechanical properties.Results indicated that theNi-Al_(2)O_(3)composite coating effectively suppressed the Mg-Sn reaction,thereby preventing the formation of Mg_(2)Sn IMC and significantlyenhancing joint strength.In joints with a Ni-Al_(2)O_(3)composite coating containing 50 mL/L Al_(2)O_(3)nano sol,no Mg_(2)Sn IMC was detectedafter 50 min of holding at 260℃,achieving a maximum shear strength of approximately 67.2 MPa.Increasing the Al_(2)O_(3)concentrationfurther expanded the soldering process window.For the joint with Ni-Al_(2)O_(3)(100 mL/L Al_(2)O_(3)nano sol)composite coating held at 260℃for 70 min,the coating was dissolved to a thickness of about 5.8μm,but no Mg_(2)Sn IMC was observed.The Ni-based solid solution formednear the coating/solder interface was strengthened,leading to fractures occurring within the SAC solder,and the maximum shear strengthfurther increased to 73.9 MPa.The strengthening mechanism of the joints facilitated by using the Ni-Al_(2)O_(3)composite coating was revealedby comparing with pure Ni-assisted joints.Therefore,employing a Ni-Al_(2)O_(3)composite coating as a barrier layer represents a promisingstrategy for inhibiting IMC formation during the joining of dissimilar metals.展开更多
In order to reduce the friction coefficient of Ni-base alloy coating and further improve its wear resistance,Ni-base alloy composite coatings modified by both graphite and TiC particles were prepared by plasma spray t...In order to reduce the friction coefficient of Ni-base alloy coating and further improve its wear resistance,Ni-base alloy composite coatings modified by both graphite and TiC particles were prepared by plasma spray technology on the surface of 45 carbon steel.The results show that friction coefficient of the composite coating is 47.45% lower than that of the Ni-base alloy coating,and the wear mass loss is reduced by 59.1%.Slip lines and severe adhesive plastic deformation are observed on the worn surface of the Ni-base alloy coating,indicating that the wear mechanisms of the Ni-base alloy coating are multi-plastic deformation wear and adhesive wear.A soft transferred layer abundant in graphite and ferric oxide is developed on the worn surface of the composite coating,which reduces the friction coefficient and wear loss in a great deal.The main wear mechanism of the composite coating is fatigue delamination of the transferred layer.展开更多
The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and trib...The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and tribological properties of the composite coatings were researched. The results show that the composite coatings mainly consist of γ-Ni, α-Al2O3, γ-Al2O3 and rutile-TiO2 etc, and exhibit lower friction coefficients and wear losses than the Ni-based alloy coatings at different loads and speeds. The composite coating bears low contact stress at 3 N and its wear mechanism is micro-cutting wear. As loads increase to 6-12 N, the contact stress is higher than the elastic limit stress of worn surface, and the wear mechanisms change into multi-plastic deformation wear, micro-brittle fracture wear and abrasive wear. With the increase of speeds, the contact temperature of worn surface increases. The composite coating experiences multi-plastic deformation wear, fatigue wear and adhesive wear.展开更多
TiN-matrix composite coating was prepared on 45# steel by reactive high-velocity oxy-fuel （HVOF） spraying. Its microstructure, phase composition, micro-hardness, corrosion resistance in 3.5% NaC1 solution and wear r...TiN-matrix composite coating was prepared on 45# steel by reactive high-velocity oxy-fuel （HVOF） spraying. Its microstructure, phase composition, micro-hardness, corrosion resistance in 3.5% NaC1 solution and wear resistance were analyzed. The results suggest that the TiN-matrix composite coating is well bonded with the substrate. The micro-hardness measured decreases with the increase of applied test loads. And the micro-hardness of the coating under heavy loads is relatively high. The TiN-matrix composite coating exhibits an excellent corrosion resistance in 3.5% NaC1 solution. The corrosion potential of coating is positive and the passivation zone is broad, which indicates that the TiN-matrix composite coating is stable in the electrolyte and provides excellent protection to the substrate. The wear coefficient of the coating under all loads maintains at 0.49-0.50. The wear mechanism of the coating is revealed to be three-body abrasive wear. Yet the failure forms of TiN-matrix composite coating under different loads have an obvious difference. The failure form of coating under light loads is particle spallation due to the stress concentration while that of coating under heavy loads is crackin~ between inter-lamellae.展开更多
In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology ...In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology and composition wereexamined using SEM, EDS and XRD, and the corrosion resistance was checked by electrochemical technology. The results indicatethat TiN nanoparticles were doped successfully in the Ni-P matrix after a series of complex pretreatments including activation, zincimmersion and pre-electroplating, which enhances the stability of magnesium alloy in electrolyte and the adhesion betweenmagnesium alloy and composite coating. The microhardness of the Ni-P coating increases dramatically by adding TiN nanoparticlesand subsequent heat treatment. The corrosion experimental results indicate that the corrosion resistance of Ni-P-TiN compositecoating is much higher than that of uncoated AZ91D magnesium alloy and similar with Ni-P coating in short immersion time.However, TiN nanoparticles play a significant role in long-term corrosion resistance of composite coatings.展开更多
Multi-walled carbon nanotubes （MWNTs） were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribologi...Multi-walled carbon nanotubes （MWNTs） were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribological performances of the composite coatings under dry condition were investigated in comparison with 45 steel and conventional Ni-P coating, Micrographs show that short MWNTs with uniform length and open tips were obtained through the wet-milling process. The results of wear test reveal that the Ni-P-MWNTs composite coatings posses much better friction reduction and anti-wear performances when compared with 45 steel and Ni-P coating. Within the MWNTs content range of 0.74%-1.97%, the friction coefficient and the volume wear rate of the composite coatings decrease gradually and reach the minimum values of 0.08 and 6.22x10-15 m3/（N.m）, respectively. The excellent tribological performances of the composite coatings can be attributed to the introduction of MWNTs, which play both roles of reinforcements and solid lubricant during the wear process.展开更多
文摘Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited on to a steel substrate by the successive deposition of zinc and Zn-Ni alloy sublayers from dual baths. The coated samples were evaluated in terms of the surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The microstructural characteristics that were examined using the field emission gun scanning electron microscopy （FEGSEM） confirmed the layered structure, grain refinement of the zinc and Zn-Ni alloy CMM coatings, and revealed the existence of microcracks caused by the internal stress in the thick Zn-Ni alloy sublayers. The corrosion resistance that was evaluated by means of the salt spray test shows that the zinc and Zn-Ni alloy CMM coatings were more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy of the same thickness. The possible reasons for the better protective performance of Zn-Ni/Zn CMM coatings were given on the basis of the analysis on the micrographic features of zinc and Zn-Ni alloy CMM eoatings after the corrosion test. A probable corrosion mechanism of zinc and Zn-Ni alloy CMM coatings was also proposed.
基金supported by the National Natural Science Foundation of China under Grant Nos.51271191,51571205 and 51401209
文摘Polycrystalline Cr2AlC coatings were prepared on M38G superalloy using a two-step method consisting of magnetron sputtering from Cr-Al-C composite targets at room temperature and subsequent annealing at 620 ℃. Particularly, various targets synthesized by hot pressing mixture of Cr, Al, and C powders at 650-1000 ℃ were used. It was found that regardless of the phase compositions and density of the com- posite targets, when the molar ratio of Cr：Al：C in the starting materials was 2：1：1, phase-pure crystalline Cr2AlC coatings were prepared by magnetron sputtering and post crystallization. The Cr2AIC coatings were dense and crack-free and had a duplex structure. The adhesion strength of the coating deposited on M38G superalloy from the 800 ℃ hot-pressed target and then annealed at 620 ℃ for 20 h in Ar exceeded 82 ± 6 MPa, while its hardness was 12 ± 3 GPa.
文摘Zinc and Zn-Ni alloy compositionally modulated multilayer （CMM） coatings were electrodeposited from dual baths. The coated samples were evaluated in terms of surface appearance, surface and cross-sectional morphologies, as well as corrosion resistance. The results obtained from the salt spray test show that the zinc and Zn-Ni alloy CMM coatings are more corrosion-resistant than the monolithic coatings of zinc or Zn-Ni alloy alone with a similar thickness. The corrosion potential measurement and anodic polarisation tests were undertaken to examine the probable corrosion mechanisms of zinc and Zn-Ni alloy CMM coatings. Analysis on the micrographic features of zinc and Zn-Ni alloy CMM coatings after the corrosion test explains the probable reasons why the Zn-Ni/Zn CMM coatings have a better protective performance. Surface morphologies and compositional analysis of the remaining coating material of Zn-Ni alloy deposit after the corrosion test confirms the dezincification mechanism of the Zn-Ni alloy deposit during the corrosion process.
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 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.
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.
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supported by the National Key Research and Development Programme(2023YFB3408200)the National Nature Science Foundation of China(52201076 and 52471077)+2 种基金the Guangdong Provincial Key R&D Programme(2023B0909020002)the Guangdong Basic and Applied Basic Research Foundation(2021A1515111065,2021B1515120014 and 2022A1515010934)the Fundamental Research Funds for the Central Universities(21623216 and 11623216).
文摘The corrosion behavior of Ni-Co-CeO_(2) composite coating was investigated under a simulated high-temperature marine atmosphere alongside Ni-Co coating. The corrosion kinetics, phase composition and microstructure evolution of the coatings were analyzed. A multi-layered oxide scale formed due to the synergistic corrosion by H_(2)O and NaCl. The growth mechanism of the Co_(3)O_(4), Fe_(3)O_(4), Fe_(2)O3, CoFe_(2)O_(4), NiFe_(2)O_(4) and NiO in the scale was proposed according to the distribution of the CeO_(2) particles. Compared to Ni-Co cating, the Ni-Co-CeO_(2) coating exhibited superior corrosion resistance in the H_(2)O/NaCl steam, which is beacause the CeO_(2) exerted a blocking effect on retarding the diffusion of Fe atoms and corrosive medium, contributing to a reduced corrosion rate and an improved oxide adhesion compared to Ni-Co coating.
基金support from the National Natural Science Foundation of China(grant numbers 52275385 and U2167216).
文摘Combining Mg and Al dissimilar metals further reduces structural weight,but the formation of intermetallic compounds(IMCs)affectsAl/Mg joint properties.To prevent IMCs,a Ni-Al_(2)O_(3)composite coating was pre-plated on the Mg alloy substrate,and then Sn_(3.0)Ag_(0.5)Cu(SAC 305)solder was utilized to facilitate the joining of AZ31 Mg/6061 Al through ultrasonic-assisted soldering.We investigated the impactof Al_(2)O_(3)nano sol content in the coating on microstructure evolution,IMCs formation,and mechanical properties.Results indicated that theNi-Al_(2)O_(3)composite coating effectively suppressed the Mg-Sn reaction,thereby preventing the formation of Mg_(2)Sn IMC and significantlyenhancing joint strength.In joints with a Ni-Al_(2)O_(3)composite coating containing 50 mL/L Al_(2)O_(3)nano sol,no Mg_(2)Sn IMC was detectedafter 50 min of holding at 260℃,achieving a maximum shear strength of approximately 67.2 MPa.Increasing the Al_(2)O_(3)concentrationfurther expanded the soldering process window.For the joint with Ni-Al_(2)O_(3)(100 mL/L Al_(2)O_(3)nano sol)composite coating held at 260℃for 70 min,the coating was dissolved to a thickness of about 5.8μm,but no Mg_(2)Sn IMC was observed.The Ni-based solid solution formednear the coating/solder interface was strengthened,leading to fractures occurring within the SAC solder,and the maximum shear strengthfurther increased to 73.9 MPa.The strengthening mechanism of the joints facilitated by using the Ni-Al_(2)O_(3)composite coating was revealedby comparing with pure Ni-assisted joints.Therefore,employing a Ni-Al_(2)O_(3)composite coating as a barrier layer represents a promisingstrategy for inhibiting IMC formation during the joining of dissimilar metals.
文摘In order to reduce the friction coefficient of Ni-base alloy coating and further improve its wear resistance,Ni-base alloy composite coatings modified by both graphite and TiC particles were prepared by plasma spray technology on the surface of 45 carbon steel.The results show that friction coefficient of the composite coating is 47.45% lower than that of the Ni-base alloy coating,and the wear mass loss is reduced by 59.1%.Slip lines and severe adhesive plastic deformation are observed on the worn surface of the Ni-base alloy coating,indicating that the wear mechanisms of the Ni-base alloy coating are multi-plastic deformation wear and adhesive wear.A soft transferred layer abundant in graphite and ferric oxide is developed on the worn surface of the composite coating,which reduces the friction coefficient and wear loss in a great deal.The main wear mechanism of the composite coating is fatigue delamination of the transferred layer.
文摘The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and tribological properties of the composite coatings were researched. The results show that the composite coatings mainly consist of γ-Ni, α-Al2O3, γ-Al2O3 and rutile-TiO2 etc, and exhibit lower friction coefficients and wear losses than the Ni-based alloy coatings at different loads and speeds. The composite coating bears low contact stress at 3 N and its wear mechanism is micro-cutting wear. As loads increase to 6-12 N, the contact stress is higher than the elastic limit stress of worn surface, and the wear mechanisms change into multi-plastic deformation wear, micro-brittle fracture wear and abrasive wear. With the increase of speeds, the contact temperature of worn surface increases. The composite coating experiences multi-plastic deformation wear, fatigue wear and adhesive wear.
基金Project(KFJJ10-15M) supported by the Open Fund of State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,ChinaProject(E2013208101) supported by the Nature Science Fund of Hebei Province,China+1 种基金Project(Z2012100) supported by Colleges and Universities Science and Technology Research Fund of Hebei Province,ChinaProject supported by the Outstanding Youth Fund of Hebei University of Science and Technology,China
文摘TiN-matrix composite coating was prepared on 45# steel by reactive high-velocity oxy-fuel （HVOF） spraying. Its microstructure, phase composition, micro-hardness, corrosion resistance in 3.5% NaC1 solution and wear resistance were analyzed. The results suggest that the TiN-matrix composite coating is well bonded with the substrate. The micro-hardness measured decreases with the increase of applied test loads. And the micro-hardness of the coating under heavy loads is relatively high. The TiN-matrix composite coating exhibits an excellent corrosion resistance in 3.5% NaC1 solution. The corrosion potential of coating is positive and the passivation zone is broad, which indicates that the TiN-matrix composite coating is stable in the electrolyte and provides excellent protection to the substrate. The wear coefficient of the coating under all loads maintains at 0.49-0.50. The wear mechanism of the coating is revealed to be three-body abrasive wear. Yet the failure forms of TiN-matrix composite coating under different loads have an obvious difference. The failure form of coating under light loads is particle spallation due to the stress concentration while that of coating under heavy loads is crackin~ between inter-lamellae.
基金Projects(51171172,51131005)supported by the National Natural Science Foundation of ChinaProject(R16E010001)supported by Zhejiang Provincial Natural Science Foundation of China+1 种基金Project(2015QNA3011)supported by Fundamental Research Funds for the Central Universities,ChinaProject(14DZ2261000)supported by Science and Technology Commission of Shanghai Municipality,China
文摘In order to improve the corrosion resistance and microhardness of AZ91D magnesium alloy, TiN nanoparticles were addedto fabricate Ni-P-TiN composite coating by electrodeposition. The surface, cross-section morphology and composition wereexamined using SEM, EDS and XRD, and the corrosion resistance was checked by electrochemical technology. The results indicatethat TiN nanoparticles were doped successfully in the Ni-P matrix after a series of complex pretreatments including activation, zincimmersion and pre-electroplating, which enhances the stability of magnesium alloy in electrolyte and the adhesion betweenmagnesium alloy and composite coating. The microhardness of the Ni-P coating increases dramatically by adding TiN nanoparticlesand subsequent heat treatment. The corrosion experimental results indicate that the corrosion resistance of Ni-P-TiN compositecoating is much higher than that of uncoated AZ91D magnesium alloy and similar with Ni-P coating in short immersion time.However, TiN nanoparticles play a significant role in long-term corrosion resistance of composite coatings.
基金Project (JPPT-115-5-1759) supported by the National Defense Science and Technology Industry Committee of China Project (20090162120080) supported by Research Fund for the Doctoral Program of Higher Education of ChinaProject (2010FJ3012) supported by the Program of Science and Technology of Hunan Province, China
文摘Multi-walled carbon nanotubes （MWNTs） were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribological performances of the composite coatings under dry condition were investigated in comparison with 45 steel and conventional Ni-P coating, Micrographs show that short MWNTs with uniform length and open tips were obtained through the wet-milling process. The results of wear test reveal that the Ni-P-MWNTs composite coatings posses much better friction reduction and anti-wear performances when compared with 45 steel and Ni-P coating. Within the MWNTs content range of 0.74%-1.97%, the friction coefficient and the volume wear rate of the composite coatings decrease gradually and reach the minimum values of 0.08 and 6.22x10-15 m3/（N.m）, respectively. The excellent tribological performances of the composite coatings can be attributed to the introduction of MWNTs, which play both roles of reinforcements and solid lubricant during the wear process.
