To improve the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites at 1700°C in air,CeO_(2) was introduced to improve oxygen blocking and its mechanism was investigated.During the rapid oxida...To improve the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites at 1700°C in air,CeO_(2) was introduced to improve oxygen blocking and its mechanism was investigated.During the rapid oxidation stage,CeO_(2) accelerated the formation of a multiphase glass layer on the coating surface.The maximum oxidation rates of CeO_(2)-HfB2-SiC coatings with 1%,3%,and 5%CeO_(2) were 24.1%,20.3%,and 53.2%higher than that of the unmodified HfB2-SiC coating,respectively.In the stable oxidation stage,the maximum oxidation rates of coatings with 1%and 3%CeO_(2) decreased by 31.4%and 21.9%,respectively,demonstrating adequate inert protection.CeO_(2) is a“coagulant”and“stabilizer”in the composite glass layer.However,increasing the CeO_(2) content accelerates the reaction between the SiO_(2) glass phase and SiC,leading to a higher SiO_(2) consumption and reduced self-healing ability of the glass layer.The 1%CeO_(2)-60%HfB2-39%SiC coating showed improved glass layer viscosity and stability,moderate SiO_(2) consumption,and better self-healing ability,significantly boosting the oxidation protection of the coating.展开更多
To verify the wear resistance and erosion resistance of Ti-doped Ta_(2)O_(5)coating(TTO),a series of TTOs were prepared by magnetron sputtering technology by controlling the power of the Ti target.The change of growth...To verify the wear resistance and erosion resistance of Ti-doped Ta_(2)O_(5)coating(TTO),a series of TTOs were prepared by magnetron sputtering technology by controlling the power of the Ti target.The change of growth structure,microstructure,and tribological properties of TTOs with Ti target power was studied.After the erosion test,the variation of erosion damage behavior of TTOs with mechanical properties under different erosion conditions was further studied.The results show that the TTOs eliminate the roughness,voids,and defects in the material due to the mobility of the adsorbed atoms during the growth process,and a flat and dense smooth surface is obtained.Tribological tests show that the TTOs are mainly characterized by plastic deformation and microcrack wear mechanism.Higher Ti target power can improve the wear resistance of TTOs.Erosion test results reveal that the impact crater,furrow,micro-cutting,brittle spalling,and crack formation are the main wear mechanisms of the TTOs samples under erosion conditions.展开更多
The effect of W-doping on the structure and properties of TiAlSiN coatings was investigated through scanning electron microscopy,X-ray diffraction,differential scanning calorimetry,and nanoindentation.Tungsten doping ...The effect of W-doping on the structure and properties of TiAlSiN coatings was investigated through scanning electron microscopy,X-ray diffraction,differential scanning calorimetry,and nanoindentation.Tungsten doping in the coatings forms both substitution solid solution of Ti and/or Al in TiAlN and W simple substance.W-addition improves the surface quality of the coatings.Ti_(0.46)Al_(0.45)Si_(0.09)N,Ti_(0.43)Al_(0.46)Si_(0.08)W_(0.03)N,and Ti_(0.41)Al_(0.46)Si_(0.07)W_(0.06)N present similar hardness of(29.1±0.4),(29.7±1.1),and(30.2±1.0)GPa,respectively.During annealing,Ti_(0.41)Al_(0.46)Si_(0.07)W_(0.06)N achieves peak hardness of(35.3±1.0)GPa at 1100℃,whereas those of Ti_(0.46)Al_(0.45)Si_(0.09)N and Ti_(0.43)Al_(0.46)Si_(0.08)W_(0.03)N are only(33.1±0.8)and(33.9±0.8)GPa at 1000℃.Furthermore,moderate W-addition(3 at.%)upgrades the oxidation resistance of TiAlSiN.After oxidation at 1000℃for 10 h,the oxide thicknesses of Ti_(0.46)Al_(0.45)Si_(0.09)N,Ti_(0.43)Al_(0.46)S_(i0.08)W_(0.03)N,and Ti_(0.41)Al_(0.46)Si_(0.07)W_(0.06)N are~0.70,~0.52,and~0.90μm,respectively.展开更多
The poor corrosion resistance of magnesium(Mg)and its alloys limits their application in various fields.Micro arc oxidation(MAO)coatings can improve the corrosion resistance,but the pore defects and low surface hardne...The poor corrosion resistance of magnesium(Mg)and its alloys limits their application in various fields.Micro arc oxidation(MAO)coatings can improve the corrosion resistance,but the pore defects and low surface hardness make them susceptible to wear and accelerated corrosion during usage.In this study,a ZrO_(2)nanoparticles doped-MAO coating is prepared on the ZK61 Mg alloy by utilizing an MgF_(2)passivation layer to prevent ablation.The ZrO_(2)nanoparticles re-melt and precipitate due to local discharging,which produces evenly dispersed nanocrystals in the MAO coating.As a result,the hardness of the MAO coating with the appropriate ZrO_(2)concentration increases by over 10 times,while the wear rate decreases and corrosion resistance increases.With increasing ZrO_(2)concentrations,the corrosion potentials increase from−1.528 V of the bare ZK61 Mg alloy to−1.184 V,the corrosion current density decreases from 1.065×10^(–4)A cm^(–2)to 3.960×10^(–8)A cm^(–2),and the charge transfer resistance increases from 3.41×10^(2)Ωcm^(2)to 6.782×10^(5)Ωcm^(2).Immersion tests conducted in a salt solution for 28 d reveal minimal corrosion in contrast to severe corrosion on the untreated ZK61 Mg alloy.ZrO_(2)nanoparticles improve the corrosion resistance of MAO coatings by sealing pores and secondary strengthening of the corrosion product layer.展开更多
Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines pla...Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition(PEUMS-PVD)and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO_(2)nanotubes/Ti_(3)AlC_(2)coating on the surface of Cu substrates.This novel strategy enhances the corrosion resistance of copper substrates in marine environments,with corrosion current densities of up to 4.5643×10^(−8)A/cm^(2).Among them,the doping of nano-aluminum particles makes the coating self-healing.The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise,and revealed that during the initial stages of coating immersion,uniform corrosion predominates,with a minor occurrence of localized corrosion.展开更多
The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties ...The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.展开更多
Proton exchange membrane water electrolysis(PEMWE)is one of the most promising strategies to pro-duce green hydrogen energy,and it is crucial to exploit highly conductive and good corrosion-resistant coatings on bipol...Proton exchange membrane water electrolysis(PEMWE)is one of the most promising strategies to pro-duce green hydrogen energy,and it is crucial to exploit highly conductive and good corrosion-resistant coatings on bipolar plates(BPs),one of the core components in PEMWE cells.In this work,NbN coatings are deposited on Ti BPs by magnetron sputtering to improve the corrosion resistance and conductivity,for which the critical process parameters,such as the working pressure,partial nitrogen pressure and de-position temperature are well optimized.It is found that the compact microstructure,highly conductive δ-NbN and uniform nanoparticles play a dominant role in the synergistic improvement of the corrosion resistance and electrical conductivity of NbN coatings.The optimized NbN coatings exhibit excellent cor-rosion resistance with the low corrosion current density of 1.1×10^(-8) A cm^(-2),a high potential value of-0.005 V vs.SCE and a low ICR value of 15.8 mΩcm2@1.5 MPa.Accordingly,NbN coatings can be a promising candidate for the development of the low-cost and high-anti-corrosion Ti BPs of PEMWE.展开更多
Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the ...Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the lattice to widen the(003) plane to 0.4746 nm with a lower cationic disordered degree of 1.87%.Moreover,the surface residual lithium salts are treated by H_3PO_4 to generate a uniform Li_(3)PO_(4) coating layer of approximately 11.41 nm,which completely covers on the surface of secondary spherical particles to improve the interfacial stability.At 25℃,the NCM-KP electrode delivers a discharge specific capacity of 148.9 mAh·g^(-1) with a remarkable capacity retention ratio of 84.1% after 200 cycles at 1.0C and retains a high reversible specific capacity of 154.4 mAh·g^(-1) at 5.0C.Even at 1.0C and 60℃,it can maintain a reversible discharge specific capacity of 114.6 mAh·g^(-1) with 0.21% of capacity decay per cycle after 200 cycles,which is significantly lower than 0.40% for the pristine NCM powders.Importantly,the charge transfer resistance of 238.89 Ω for the NCM-KP electrode is significantly lower than 947.41 Ω for the pristine NCM one by restricting the interfacial side reactions.Therefore,combining K+doping and Li_(3)PO_(4) coating is an effective strategy to enable the significant improvement of the electrochemical property of high-nickel cathode materials,which may be mainly attributed to the widened diffusion pathway and the formed Li_(3)PO_(4) protective layer,thus promoting Li~+diffusion rate and preventing the erosion of HF.展开更多
Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion pro...Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness(0 g/L volatile organic compounds).Nevertheless,several intrinsic deficiencies require improvement,such as fragile mechanical properties and defects(macro and micro),resulting in the continuous deterioration of comprehensive coating performances.In this work,a novel nanocomposite coating with mechanical enhancement,intelligent self-reporting,and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure(GO-CeMOF-P/M).Notably,the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness,which boosts the tensile strength(32.1 MPa/8.5%)and dry adhesion force(5.8 MPa)of the coating.Additionally,the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating,making it especially suitable for a variety of practical marine applications.Furthermore,following immersion of 80 d in the aggressive environment,Zf=0.01 Hz value of GO-CeMOF-P/M-EP coating is 1.2×10^(10)Ωcm^(2),which is 164.4 times larger than that of EP coating(7.3×10^(7)Ωcm^(2)),demonstrating remarkably strengthened anti-corrosion ability.Consequently,by offering an intriguing design strategy,the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.展开更多
The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has...The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has been employed as a coating agent.The SEM micrographs revealed distinct features of both pure AN and NC,contrasting with the irregular granular surface topography of the coated AN particles,demonstrating the adherence of NC on the AN surface.Structural analysis via infrared spectroscopy(IR)demonstrated a successful association of AN and NC,with slight shifts observed in IR bands indicating interfacial interactions.Powder X-ray Diffraction(PXRD)analysis further elucidated the structural changes induced by the coating process,revealing that the NC coating altered the crystallization pattern of its pure form.Thermal analysis demonstrates distinct profiles for pure and coated AN,for which the coated sample exhibits a temperature increase and an enthalpy decrease of the room temperature allotropic transition by 6℃,and 36%,respectively.Furthermore,the presence of NC coating alters the intermolecular forces within the composite system,leading to a reduction in melting enthalpy of coated AN by~39%compared to pure AN.The thermal decomposition analysis shows a two-step thermolysis process for coated AN,with a significant increase in the released heat by about 78%accompanied by an increase in the activation barrier of NC and AN thermolysis,demonstrating a stabilized reactivity of the AN-NC particles.These findings highlight the synergistic effect of NC coating on AN particles,which contributed to a structural and reactive stabilization of both AN and NC,proving the potential application of NC-coated AN as a strategically advantageous oxidizer in composite solid propellant formulations.展开更多
Diamond coatings possess numerous excellent properties,making them desirable materials for high-performance surface applications.However,without a revolutionary surface modification method,the surface roughness and fr...Diamond coatings possess numerous excellent properties,making them desirable materials for high-performance surface applications.However,without a revolutionary surface modification method,the surface roughness and friction behavior of diamond coatings can impede their ability to meet the demanding requirements of advanced engineering surfaces.This study proposed the thermal stress control at coating interfaces and demonstrated a novel process of precise graphenization on conventional diamond coatings surface through laser induction and mechanical cleavage,without causing damage to the metal substrate.Through experiments and simulations,the influence mechanism of surface graphitization and interfacial thermal stress was elucidated,ultimately enabling rapid conversion of the diamond coating surface to graphene while controlling the coating’s thickness and roughness.Compared to the original diamond coatings,the obtained surfaces exhibited a 63%-72%reduction in friction coefficients,all of which were below 0.1,with a minimum of 0.06,and a 59%-67%decrease in specific wear rates.Moreover,adhesive wear in the friction counterpart was significantly inhibited,resulting in a reduction in wear by 49%-83%.This demonstrated a significant improvement in lubrication and inhibition of mechanochemical wear properties.This study provides an effective and cost-efficient avenue to overcome the application bottleneck of engineered diamond surfaces,with the potential to significantly enhance the performance and expand the application range of diamond-coated components.展开更多
Polyurethane-fluorinated polysiloxane(PU-^(F)PDMS)with high-strength,high-bonding and low surface en-ergy is synthesized as the matrix,and the PU-^(F)PDMS/MCs/Ag marine anti-fouling coating on the sur-face of imitatio...Polyurethane-fluorinated polysiloxane(PU-^(F)PDMS)with high-strength,high-bonding and low surface en-ergy is synthesized as the matrix,and the PU-^(F)PDMS/MCs/Ag marine anti-fouling coating on the sur-face of imitation crab shells is constructed by assembling butenolide@1,1-stilbene-modified hydrolyzed polyglycidyl methacrylate/graphene oxide microcapsules(Bu@PGMAm/GO MCs)with compact multi-shell structure and Ag nanoparticles(AgNPs)step by step on the PU-^(F)PDMS matrix.The PU-^(F)PDMS/MCs/Ag bionic anti-fouling coatings achieve long-term and stable anti-fouling effect under the combination of robust low-surface-energy PU-^(F)PDMS matrix,steady-state sustained release of butenolide encapsulated by the compact multi-shell,bionic surface formed by the microcapsules and AgNPs,and the release of Ag^(+).The shear strength,tensile strength,and elongation at break of the PU-^(F)PDMS/MCs/Ag are 3.53 MPa,6.7 MPa,and 192.83%,respectively.Its static contact angle and sliding angle are 161.8°and 3.6°,respectively.The antibacterial rate of PU-^(F)PDMS/MCs/Ag against Escherichia coli,Staphylococcus aureus,and Candida albicans can reach 100%.Compared with glass blank,PU,PU-^(F)PDMS,PU-^(F)PDMS/Ag,and PU-^(F)PDMS/MCs,both the adhesion number and coverage percentage of chlorella adhere to PU-^(F)PDMS/MCs/Ag are the minimum values,which are 600 cell mm^(-2) and 1.53%,respectively.After 6 months of marine field test,the primer blank,PU,PU-^(F)PDMS all show different degrees of attachment by shellfish,spirorbis,al-gae and other biofouling,while the PU-^(F)PDMS/MCs/Ag coating is still not covered with biofouling,while the PU-^(F)PDMS/MCs/Ag coatings still exhibit little attachment of marine fouling.The PU-^(F)PDMS/MCs/Ag bionic anti-fouling coatings are expected to be widely used in the fields of anti-fouling,anti-icing,anti-fogging,drag reduction,self-cleaning,and antibacterial.展开更多
WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content o...WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content on microstructure and wear property of the composite coatings was studied in detail.Large numbers of carbides with four main types:primary carbide crystals,eutectic structures,massive crystals growing along the periphery of the remaining WC particles and incompletely fused WC particles,were found to exist in the WC/CoCrFeNiMo composite coatings.With increasing WC content,the microhardness of coatings is gradually improved while the average friction coefficients follow the opposite trend due to solid solution strengthening and second phase strengthening effect.The maximum microhardness and minimum friction coefficient are HV_(0.2)689.7 and 0.72,respectively,for the composite coating with 30 wt.%WC,the wear resistance of the substrate is improved significantly,the wear mechanisms are spalling wear and abrasive wear due to their high microhardness.展开更多
We have developed a superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating on the surface of Mg alloy.This composite comprised a tungstate-intercalated(LDH-W)underlayer that was grown at low temperatu...We have developed a superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating on the surface of Mg alloy.This composite comprised a tungstate-intercalated(LDH-W)underlayer that was grown at low temperature(relative to hydrothermal reaction conditions)under atmospheric pressure and an outer polysiloxane layer created from a solution containing perfluorodecyltrimethoxysilane(PFDTMS)using a simple immersion method.The successful intercalation of tungstate into the LDH phase and the following formation of the polysiloxane layer were confirmed through X-ray diffraction(XRD),Fourier transform infrared(FTIR)spectroscopy,and X-ray photoelectron spectroscopy(XPS).The corrosion resistance of the LDH-W film,both before and after the PFDTMS modification,was evaluated using electrochemical impedance spectroscopy(EIS),Tafel curves,and immersion experiments.The results showed that Mg coated with LDH-W/PFDTMS exhibited significantly enhanced corrosion protection compared to the unmodified LDHW film,with no apparent signs of corrosion after exposure to 3.5wt%NaCl solution for 15 d.Furthermore,the LDH-W/PFDTMS coating demonstrated superior superhydrophobicity and self-cleaning properties against water and several common beverages,as confirmed by static contact angle and water-repellency tests.These results offer valuable insights into preparing superhydrophobic and corrosion-resistant LDH-based composite coatings on Mg alloy surfaces under relatively mild reaction conditions.展开更多
Magnesium and its alloys have gained relevance for their light-weight combined with a high value of strength-to-weight ratio,which makes them useful in fields such as aerospace,automotive as well as biomedical enginee...Magnesium and its alloys have gained relevance for their light-weight combined with a high value of strength-to-weight ratio,which makes them useful in fields such as aerospace,automotive as well as biomedical engineering.Unfortunately,the poor corrosion resistance of Mg-alloys limits their wide acceptance.Advanced composite coatings which are self-healing,superhydrophobic anti corrosive,and wear resistant are new synthetic materials for abating these challenges.The superimposed superhydrophobic surfaces help in minimizing their water contact,thus slowing down the electrochemical reactions on the surface of the alloys,while their self-healing characteristics autonomously aid in the repair of any induced micro-crack,defect or damage towards ensuring the metal's long-term protection.In addition,the integration of wear-resistant materials further improves the durability of coatings under mechanical stress.The most recent research efforts have been directed towards the preparation of multifunctional composites,with an emphasis on nanomaterials,functional polymers,and state-of-the-art fabrication techniques in order to take advantage of their synergistic effects.Some of the methods that have so far exhibited promising potentials in fabricating these materials include the sol-gel method,layer-by-layer assembly,and plasma treatments.However,most of the fabricated products are still faced with significant challenges ranging from long-term stability to homogeneous adhesion of the coatings and their scalability for industrial applications.This review discusses the recent progress and the relationship between corrosion inhibition and self-healing efficiencies of wear resistant polymer nanocomposite coatings.Some challenges related to optimizing coating performance were also discussed.In addition,future directions ranging from the consideration of bioinspired designs,novel hybrid nanocomposite materials,and environmentally sustainable solutions integrated with smart protective coatings were also proposed as new wave technologies that can potentially revolutionize the corrosion protection offered by Mg alloys while opening up prospects for improved performance and sustainability.展开更多
Silicide coatings have proven to be promising for improving the high-temperature oxidation resistance of niobium alloy.However,the long-term protective property of single silicide coating remains a long-time endeavor ...Silicide coatings have proven to be promising for improving the high-temperature oxidation resistance of niobium alloy.However,the long-term protective property of single silicide coating remains a long-time endeavor due to the deficiency of oxygen-consuming phases,as well as the self-healing ability of the protective layer.Herein,a silicide-based composite coating is constructed on niobium alloy by incor-poration of nano-SiC particles for enhancing the high-temperature oxidation resistance.Isothermal oxi-dation results at 1250℃ for 50 h indicate that NbSi_(2)/Nb_(2)O_(5)-SiO_(2)/SiC multilayer coated sample with a low mass gain of 2.49 mg/cm^(2) shows an improved oxidation resistance compared with NbSi_(2) coating(6.49 mg/cm^(2)).The enhanced high-temperature antioxidant performance of NbSi_(2)/Nb_(2)O_(5)-SiO_(2)/SiC multi-layer coating is mainly attributed to the formation of the protective SiO_(2) self-healing film and the high-temperature diffusion behavior of NbSi_(2)/substrate.展开更多
Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates...Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates the preparation of ZnO-containing micro-arc oxidation coatings with dual functionality by incorporating nano-ZnO into MAO electrolyte.The influence of varying ZnO concentrations on the microstructure,corrosion resistance,and antibacterial properties of the coating was examined through microstructure analysis,immersion tests,electrochemical experiments,and antibacterial assays.The findings revealed that the addition of nano-ZnO significantly enhanced the corrosion resistance of the MAO-coated alloy.Specifically,when the ZnO concentration in the electrolyte was 5 g/L,the corrosion rate was more than ten times lower compared to the MAO coatings without ZnO.Moreover,the antibacterial efficacy of ZnO+MAO coating,prepared with a ZnO concentration of 5 g/L,surpassed 95%after 24 h of co-culturing with Staphylococcus aureus(S.aureus).The nano-ZnO+MAO-coated alloy exhibited exceptional degradation resistance,corrosion resistance,and antibacterial effectiveness.展开更多
Mg and its alloys show high potential to be applied as implant materials due to their superior properties like biodegradability,bioactivity,biocompatibility,and suitable mechanical behaviors.Nevertheless,the fast and ...Mg and its alloys show high potential to be applied as implant materials due to their superior properties like biodegradability,bioactivity,biocompatibility,and suitable mechanical behaviors.Nevertheless,the fast and uncontrolled degradation of Mg alloys in biological environment severely restricts their wide applications as biomedical materials.In comparison with alloying,surface coatings can not only improve corrosion resistance but also impart other bio-functional properties to achieve diverse clinical requirements.This review analyzes and summarizes the most recent developments in popular coating technologies,including micro-arc oxidation,electrophoretic deposition,chemical conversion,anodic oxidation,layered double hydroxide,and sol-gel coatings.Considering inevitable damages under complex service conditions,smart self-healing coatings are also introduced in each coating technology.The existing issues and future perspectives are finally discussed to facilitate applications of Mg alloys as biomedical materials in the medical industry.展开更多
A Cr/CoNiCrAlTaY bilayer coating was prepared on the Ti-45Al-8.5Nb alloy by plasma surface metallurgy technique.The as-prepared coating with a grain size of~2μm exhibited a dense microstructure and strong adhesion du...A Cr/CoNiCrAlTaY bilayer coating was prepared on the Ti-45Al-8.5Nb alloy by plasma surface metallurgy technique.The as-prepared coating with a grain size of~2μm exhibited a dense microstructure and strong adhesion due to metallurgical bonding,consisting of outermost Cr layer and CoNiCrAlTaY transition layer.The typical power-law relationship between mass gain and time was obtained for the coated specimens with a rate exponent of 3.18 following oxidation at 1173 K.The top Cr_(2)O_(3)film and spinel oxides(i.e.,NiCr_(2)O_(4)and CoCr_(2)O_(4))exhibited a protective effect with a low oxidation reaction rate.Interfacial analysis identified Ta precipitates(Cr_(2)Ta and TaAl_(3))and Ta oxides(Ta_(2)O_(5)and Ta_(2)O_(3)),which played an essential role in retarding rapid diffusion and enhancing adhesion and oxidation resistance.展开更多
Silicon is believed to be a critical anode material for approaching the roadmap of lithium-ion batteries due to its high specific capacity. But this aim has been hindered by the quick capacity fading of its electrodes...Silicon is believed to be a critical anode material for approaching the roadmap of lithium-ion batteries due to its high specific capacity. But this aim has been hindered by the quick capacity fading of its electrodes during repeated charge–discharge cycles. In this work, a “soft-hard”double-layer coating has been proposed and carried out on ball-milled silicon particles. It is composed of inside conductive pathway and outside elastic coating, which is achieved by decomposing a conductive graphite layer on the silicon surface and further coating it with a polymer layer.The incorporation of the second elastic coating on the inside carbon coating enables silicon particles strongly interacted with binders, thereby making the electrodes displaying an obviously improved cycling stability. As-obtained double-coated silicon anodes deliver a reversible capacity of 2280 m Ah g^(-1)at the voltage of 0.05–2 V, and maintains over 1763 mAh g^(-1)after 50 cycles. The double-layer coating does not crack after the repeated cycling, critical for the robust performance of the electrodes. In addition, as-obtained silicon particles are mixed with commercial graphite to make actual anodes for lithium-ion batteries. A capacity of 714 mAh g^(-1)has been achieved based on the total mass of the electrodes containing 10 wt.% double-coated silicon particles. Compared with traditional carbon coating or polymeric coating, the double-coating electrodes display a much better performance. Therefore, the double-coating strategy can give inspiration for better design and synthesis of silicon anodes, as well as other battery materials.展开更多
文摘To improve the oxidation resistance of HfB_(2)-SiC coatings on carbon/carbon composites at 1700°C in air,CeO_(2) was introduced to improve oxygen blocking and its mechanism was investigated.During the rapid oxidation stage,CeO_(2) accelerated the formation of a multiphase glass layer on the coating surface.The maximum oxidation rates of CeO_(2)-HfB2-SiC coatings with 1%,3%,and 5%CeO_(2) were 24.1%,20.3%,and 53.2%higher than that of the unmodified HfB2-SiC coating,respectively.In the stable oxidation stage,the maximum oxidation rates of coatings with 1%and 3%CeO_(2) decreased by 31.4%and 21.9%,respectively,demonstrating adequate inert protection.CeO_(2) is a“coagulant”and“stabilizer”in the composite glass layer.However,increasing the CeO_(2) content accelerates the reaction between the SiO_(2) glass phase and SiC,leading to a higher SiO_(2) consumption and reduced self-healing ability of the glass layer.The 1%CeO_(2)-60%HfB2-39%SiC coating showed improved glass layer viscosity and stability,moderate SiO_(2) consumption,and better self-healing ability,significantly boosting the oxidation protection of the coating.
文摘To verify the wear resistance and erosion resistance of Ti-doped Ta_(2)O_(5)coating(TTO),a series of TTOs were prepared by magnetron sputtering technology by controlling the power of the Ti target.The change of growth structure,microstructure,and tribological properties of TTOs with Ti target power was studied.After the erosion test,the variation of erosion damage behavior of TTOs with mechanical properties under different erosion conditions was further studied.The results show that the TTOs eliminate the roughness,voids,and defects in the material due to the mobility of the adsorbed atoms during the growth process,and a flat and dense smooth surface is obtained.Tribological tests show that the TTOs are mainly characterized by plastic deformation and microcrack wear mechanism.Higher Ti target power can improve the wear resistance of TTOs.Erosion test results reveal that the impact crater,furrow,micro-cutting,brittle spalling,and crack formation are the main wear mechanisms of the TTOs samples under erosion conditions.
基金financially supported by the National Natural Science Foundation of China(Nos.51775560,51771234).
文摘The effect of W-doping on the structure and properties of TiAlSiN coatings was investigated through scanning electron microscopy,X-ray diffraction,differential scanning calorimetry,and nanoindentation.Tungsten doping in the coatings forms both substitution solid solution of Ti and/or Al in TiAlN and W simple substance.W-addition improves the surface quality of the coatings.Ti_(0.46)Al_(0.45)Si_(0.09)N,Ti_(0.43)Al_(0.46)Si_(0.08)W_(0.03)N,and Ti_(0.41)Al_(0.46)Si_(0.07)W_(0.06)N present similar hardness of(29.1±0.4),(29.7±1.1),and(30.2±1.0)GPa,respectively.During annealing,Ti_(0.41)Al_(0.46)Si_(0.07)W_(0.06)N achieves peak hardness of(35.3±1.0)GPa at 1100℃,whereas those of Ti_(0.46)Al_(0.45)Si_(0.09)N and Ti_(0.43)Al_(0.46)Si_(0.08)W_(0.03)N are only(33.1±0.8)and(33.9±0.8)GPa at 1000℃.Furthermore,moderate W-addition(3 at.%)upgrades the oxidation resistance of TiAlSiN.After oxidation at 1000℃for 10 h,the oxide thicknesses of Ti_(0.46)Al_(0.45)Si_(0.09)N,Ti_(0.43)Al_(0.46)S_(i0.08)W_(0.03)N,and Ti_(0.41)Al_(0.46)Si_(0.07)W_(0.06)N are~0.70,~0.52,and~0.90μm,respectively.
基金supported by the Postdoctoral Fellowship Program of CPSF(No.GZC20231545)the China Postdoctoral Science Foundation(Nos.2024T170557 and 2023M742224)+6 种基金the Shanghai Post-doctoral Excellence Program(No.2023440)the National Natural Science Foundation of China(Nos.52127801,52401101,and 22205012)the Shenzhen Basic Research Project(Nos.JCYJ20210324120001003,JCYJ20200109144608205)the Guangdong Basic and Applied Basic Research Foundation(Nos.2020A1515011301 and 2021A1515012246)the IER Foundation(Nos.IERF202201 andIERF202202),the City University of Hong Kong Donation Research(No.DON-RMG 9229021)the Hong Kong PDFS-RGC Postdoctoral Fellowship Scheme(Nos.PDFS2122–1S08 and CityU 9061014)the Hong Kong HMRF(Health and Medical Research Fund)(Nos.2120972 and CityU 9211320).
文摘The poor corrosion resistance of magnesium(Mg)and its alloys limits their application in various fields.Micro arc oxidation(MAO)coatings can improve the corrosion resistance,but the pore defects and low surface hardness make them susceptible to wear and accelerated corrosion during usage.In this study,a ZrO_(2)nanoparticles doped-MAO coating is prepared on the ZK61 Mg alloy by utilizing an MgF_(2)passivation layer to prevent ablation.The ZrO_(2)nanoparticles re-melt and precipitate due to local discharging,which produces evenly dispersed nanocrystals in the MAO coating.As a result,the hardness of the MAO coating with the appropriate ZrO_(2)concentration increases by over 10 times,while the wear rate decreases and corrosion resistance increases.With increasing ZrO_(2)concentrations,the corrosion potentials increase from−1.528 V of the bare ZK61 Mg alloy to−1.184 V,the corrosion current density decreases from 1.065×10^(–4)A cm^(–2)to 3.960×10^(–8)A cm^(–2),and the charge transfer resistance increases from 3.41×10^(2)Ωcm^(2)to 6.782×10^(5)Ωcm^(2).Immersion tests conducted in a salt solution for 28 d reveal minimal corrosion in contrast to severe corrosion on the untreated ZK61 Mg alloy.ZrO_(2)nanoparticles improve the corrosion resistance of MAO coatings by sealing pores and secondary strengthening of the corrosion product layer.
基金Projects(42106051,42006046,U2106206) supported by the National Natural Science Foundation of ChinaProject(22373501D) supported by Hebei Provincial Key R&D Program,China。
文摘Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition(PEUMS-PVD)and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO_(2)nanotubes/Ti_(3)AlC_(2)coating on the surface of Cu substrates.This novel strategy enhances the corrosion resistance of copper substrates in marine environments,with corrosion current densities of up to 4.5643×10^(−8)A/cm^(2).Among them,the doping of nano-aluminum particles makes the coating self-healing.The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise,and revealed that during the initial stages of coating immersion,uniform corrosion predominates,with a minor occurrence of localized corrosion.
基金financially supported by the National Natural Science Foundation of China(No.52371049)the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(YESS,No.2020QNRC001)the National Science and Technology Resources Investigation Program of China(Nos.2021FY100603 and 2019FY101404)。
文摘The atmospheric corrosion monitoring(ACM)technique has been widely employed to track the real-time corrosion behavior of metal materials.However,limited studies have applied ACM to the corrosion protection properties of organic coatings.This study compared a bare epoxy coating with one containing zinc phosphate corrosion inhibitors,both applied on ACM sensors,to observe their corrosion protection properties over time.Coatings with artificial damage via scratches were exposed to immersion and alternating dry and wet environments,which allowed for monitoring galvanic corrosion currents in real-time.Throughout the corrosion tests,the ACM currents of the zinc phosphate/epoxy coating were considerably lower than those of the blank epoxy coating.The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis.This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings.Compared with the blank epoxy coating,the zinc phosphate/epoxy coating showed much-decreased ACM current values that confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.
基金supported by the National Key Re-search and Development Program of China(No.2022YFB4002100)the National Natural Science Foundation of China(No.52271136)the Natural Science Foundation of Shaanxi Province(Nos.2019TD-020 and 2021JC-06).
文摘Proton exchange membrane water electrolysis(PEMWE)is one of the most promising strategies to pro-duce green hydrogen energy,and it is crucial to exploit highly conductive and good corrosion-resistant coatings on bipolar plates(BPs),one of the core components in PEMWE cells.In this work,NbN coatings are deposited on Ti BPs by magnetron sputtering to improve the corrosion resistance and conductivity,for which the critical process parameters,such as the working pressure,partial nitrogen pressure and de-position temperature are well optimized.It is found that the compact microstructure,highly conductive δ-NbN and uniform nanoparticles play a dominant role in the synergistic improvement of the corrosion resistance and electrical conductivity of NbN coatings.The optimized NbN coatings exhibit excellent cor-rosion resistance with the low corrosion current density of 1.1×10^(-8) A cm^(-2),a high potential value of-0.005 V vs.SCE and a low ICR value of 15.8 mΩcm2@1.5 MPa.Accordingly,NbN coatings can be a promising candidate for the development of the low-cost and high-anti-corrosion Ti BPs of PEMWE.
基金financially supported by the National Natural Science Foundation of China (Nos.52274292 and 51874046)the Outstanding Youth Foundation of Hubei Province (No.2020CFA090)。
文摘Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the lattice to widen the(003) plane to 0.4746 nm with a lower cationic disordered degree of 1.87%.Moreover,the surface residual lithium salts are treated by H_3PO_4 to generate a uniform Li_(3)PO_(4) coating layer of approximately 11.41 nm,which completely covers on the surface of secondary spherical particles to improve the interfacial stability.At 25℃,the NCM-KP electrode delivers a discharge specific capacity of 148.9 mAh·g^(-1) with a remarkable capacity retention ratio of 84.1% after 200 cycles at 1.0C and retains a high reversible specific capacity of 154.4 mAh·g^(-1) at 5.0C.Even at 1.0C and 60℃,it can maintain a reversible discharge specific capacity of 114.6 mAh·g^(-1) with 0.21% of capacity decay per cycle after 200 cycles,which is significantly lower than 0.40% for the pristine NCM powders.Importantly,the charge transfer resistance of 238.89 Ω for the NCM-KP electrode is significantly lower than 947.41 Ω for the pristine NCM one by restricting the interfacial side reactions.Therefore,combining K+doping and Li_(3)PO_(4) coating is an effective strategy to enable the significant improvement of the electrochemical property of high-nickel cathode materials,which may be mainly attributed to the widened diffusion pathway and the formed Li_(3)PO_(4) protective layer,thus promoting Li~+diffusion rate and preventing the erosion of HF.
基金financially supported by the National Natural Science Foundation of China(Nos.52371088,52071347,and U20A20233)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515240007)Shenzhen Science and Technology Program(No.KJZD20230923114819041).
文摘Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness(0 g/L volatile organic compounds).Nevertheless,several intrinsic deficiencies require improvement,such as fragile mechanical properties and defects(macro and micro),resulting in the continuous deterioration of comprehensive coating performances.In this work,a novel nanocomposite coating with mechanical enhancement,intelligent self-reporting,and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure(GO-CeMOF-P/M).Notably,the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness,which boosts the tensile strength(32.1 MPa/8.5%)and dry adhesion force(5.8 MPa)of the coating.Additionally,the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating,making it especially suitable for a variety of practical marine applications.Furthermore,following immersion of 80 d in the aggressive environment,Zf=0.01 Hz value of GO-CeMOF-P/M-EP coating is 1.2×10^(10)Ωcm^(2),which is 164.4 times larger than that of EP coating(7.3×10^(7)Ωcm^(2)),demonstrating remarkably strengthened anti-corrosion ability.Consequently,by offering an intriguing design strategy,the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.
文摘The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has been employed as a coating agent.The SEM micrographs revealed distinct features of both pure AN and NC,contrasting with the irregular granular surface topography of the coated AN particles,demonstrating the adherence of NC on the AN surface.Structural analysis via infrared spectroscopy(IR)demonstrated a successful association of AN and NC,with slight shifts observed in IR bands indicating interfacial interactions.Powder X-ray Diffraction(PXRD)analysis further elucidated the structural changes induced by the coating process,revealing that the NC coating altered the crystallization pattern of its pure form.Thermal analysis demonstrates distinct profiles for pure and coated AN,for which the coated sample exhibits a temperature increase and an enthalpy decrease of the room temperature allotropic transition by 6℃,and 36%,respectively.Furthermore,the presence of NC coating alters the intermolecular forces within the composite system,leading to a reduction in melting enthalpy of coated AN by~39%compared to pure AN.The thermal decomposition analysis shows a two-step thermolysis process for coated AN,with a significant increase in the released heat by about 78%accompanied by an increase in the activation barrier of NC and AN thermolysis,demonstrating a stabilized reactivity of the AN-NC particles.These findings highlight the synergistic effect of NC coating on AN particles,which contributed to a structural and reactive stabilization of both AN and NC,proving the potential application of NC-coated AN as a strategically advantageous oxidizer in composite solid propellant formulations.
基金support from the National Natural Science Foundation of China(NSFC)[No.52475464,52475463]National Natural Science Foundation of Jiangsu Province(No.BK20231442)+4 种基金the Fundamental Research Funds for the Central Universities(No.NS2024032)the International Joint Laboratory of Sustainable Manufacturing,Ministry of Education and the Fundamental Research Funds for the Central Universities(No.NG2024007)China Scholarship Council(No.202206830048)the Foundation of the Graduate Innovation Center,Nanjing University of Aeronautics and Astronautics(No.kfjj20200510)Funding for Outstanding Doctoral Dissertation in NUAA(No.BCXJ23-09)。
文摘Diamond coatings possess numerous excellent properties,making them desirable materials for high-performance surface applications.However,without a revolutionary surface modification method,the surface roughness and friction behavior of diamond coatings can impede their ability to meet the demanding requirements of advanced engineering surfaces.This study proposed the thermal stress control at coating interfaces and demonstrated a novel process of precise graphenization on conventional diamond coatings surface through laser induction and mechanical cleavage,without causing damage to the metal substrate.Through experiments and simulations,the influence mechanism of surface graphitization and interfacial thermal stress was elucidated,ultimately enabling rapid conversion of the diamond coating surface to graphene while controlling the coating’s thickness and roughness.Compared to the original diamond coatings,the obtained surfaces exhibited a 63%-72%reduction in friction coefficients,all of which were below 0.1,with a minimum of 0.06,and a 59%-67%decrease in specific wear rates.Moreover,adhesive wear in the friction counterpart was significantly inhibited,resulting in a reduction in wear by 49%-83%.This demonstrated a significant improvement in lubrication and inhibition of mechanochemical wear properties.This study provides an effective and cost-efficient avenue to overcome the application bottleneck of engineered diamond surfaces,with the potential to significantly enhance the performance and expand the application range of diamond-coated components.
基金supported by the National Natural Science Foundation of China(Nos.52003148 and 52261045)the State Key Laboratory of Marine Resource Utilization in South China Sea,Hainan University(No.MRUKF2021023)+3 种基金the Key Research and Development Project of Shaanxi Province(No.2023-YBGY-475)the Key Scientific Research Project of Education Department of Shaanxi Province(No.22JS003)the Industrialization Project of the State Key Laboratory of Biological Resources and Ecological Environment(Cultivation)of Qinba Region(No.SXC-2310)the key cultivation project funds of Shaanxi University of Technology(No.SLGKYXM2201).
文摘Polyurethane-fluorinated polysiloxane(PU-^(F)PDMS)with high-strength,high-bonding and low surface en-ergy is synthesized as the matrix,and the PU-^(F)PDMS/MCs/Ag marine anti-fouling coating on the sur-face of imitation crab shells is constructed by assembling butenolide@1,1-stilbene-modified hydrolyzed polyglycidyl methacrylate/graphene oxide microcapsules(Bu@PGMAm/GO MCs)with compact multi-shell structure and Ag nanoparticles(AgNPs)step by step on the PU-^(F)PDMS matrix.The PU-^(F)PDMS/MCs/Ag bionic anti-fouling coatings achieve long-term and stable anti-fouling effect under the combination of robust low-surface-energy PU-^(F)PDMS matrix,steady-state sustained release of butenolide encapsulated by the compact multi-shell,bionic surface formed by the microcapsules and AgNPs,and the release of Ag^(+).The shear strength,tensile strength,and elongation at break of the PU-^(F)PDMS/MCs/Ag are 3.53 MPa,6.7 MPa,and 192.83%,respectively.Its static contact angle and sliding angle are 161.8°and 3.6°,respectively.The antibacterial rate of PU-^(F)PDMS/MCs/Ag against Escherichia coli,Staphylococcus aureus,and Candida albicans can reach 100%.Compared with glass blank,PU,PU-^(F)PDMS,PU-^(F)PDMS/Ag,and PU-^(F)PDMS/MCs,both the adhesion number and coverage percentage of chlorella adhere to PU-^(F)PDMS/MCs/Ag are the minimum values,which are 600 cell mm^(-2) and 1.53%,respectively.After 6 months of marine field test,the primer blank,PU,PU-^(F)PDMS all show different degrees of attachment by shellfish,spirorbis,al-gae and other biofouling,while the PU-^(F)PDMS/MCs/Ag coating is still not covered with biofouling,while the PU-^(F)PDMS/MCs/Ag coatings still exhibit little attachment of marine fouling.The PU-^(F)PDMS/MCs/Ag bionic anti-fouling coatings are expected to be widely used in the fields of anti-fouling,anti-icing,anti-fogging,drag reduction,self-cleaning,and antibacterial.
基金Project(2021YFC2801904)supported by the National Key R&D Program of ChinaProject(KY10100230067)supported by the Basic Product Innovation Research Project,China+3 种基金Projects(52271130,52305344)supported by the National Natural Science Foundation of ChinaProjects(ZR2020ME017,ZR2020QE186)supported by the Natural Science Foundation of Shandong Province,ChinaProjects(AMGM2024F11,AMGM2021F10,AMGM2023F06)supported by the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai,ChinaProject(KY90200210015)supported by Leading Scientific Research Project of China National Nuclear Corporation(CNNC),China。
文摘WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content on microstructure and wear property of the composite coatings was studied in detail.Large numbers of carbides with four main types:primary carbide crystals,eutectic structures,massive crystals growing along the periphery of the remaining WC particles and incompletely fused WC particles,were found to exist in the WC/CoCrFeNiMo composite coatings.With increasing WC content,the microhardness of coatings is gradually improved while the average friction coefficients follow the opposite trend due to solid solution strengthening and second phase strengthening effect.The maximum microhardness and minimum friction coefficient are HV_(0.2)689.7 and 0.72,respectively,for the composite coating with 30 wt.%WC,the wear resistance of the substrate is improved significantly,the wear mechanisms are spalling wear and abrasive wear due to their high microhardness.
基金supported by the National Natural Science Foundation of China(No.52271073)the Sichuan Provincial Natural Science Foundation for Distinguished Young Scholars,China(No.2024NSFJQ0034)the Innovation Team Funds of China West Normal University(No.KCXTD2024-1)。
文摘We have developed a superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating on the surface of Mg alloy.This composite comprised a tungstate-intercalated(LDH-W)underlayer that was grown at low temperature(relative to hydrothermal reaction conditions)under atmospheric pressure and an outer polysiloxane layer created from a solution containing perfluorodecyltrimethoxysilane(PFDTMS)using a simple immersion method.The successful intercalation of tungstate into the LDH phase and the following formation of the polysiloxane layer were confirmed through X-ray diffraction(XRD),Fourier transform infrared(FTIR)spectroscopy,and X-ray photoelectron spectroscopy(XPS).The corrosion resistance of the LDH-W film,both before and after the PFDTMS modification,was evaluated using electrochemical impedance spectroscopy(EIS),Tafel curves,and immersion experiments.The results showed that Mg coated with LDH-W/PFDTMS exhibited significantly enhanced corrosion protection compared to the unmodified LDHW film,with no apparent signs of corrosion after exposure to 3.5wt%NaCl solution for 15 d.Furthermore,the LDH-W/PFDTMS coating demonstrated superior superhydrophobicity and self-cleaning properties against water and several common beverages,as confirmed by static contact angle and water-repellency tests.These results offer valuable insights into preparing superhydrophobic and corrosion-resistant LDH-based composite coatings on Mg alloy surfaces under relatively mild reaction conditions.
文摘Magnesium and its alloys have gained relevance for their light-weight combined with a high value of strength-to-weight ratio,which makes them useful in fields such as aerospace,automotive as well as biomedical engineering.Unfortunately,the poor corrosion resistance of Mg-alloys limits their wide acceptance.Advanced composite coatings which are self-healing,superhydrophobic anti corrosive,and wear resistant are new synthetic materials for abating these challenges.The superimposed superhydrophobic surfaces help in minimizing their water contact,thus slowing down the electrochemical reactions on the surface of the alloys,while their self-healing characteristics autonomously aid in the repair of any induced micro-crack,defect or damage towards ensuring the metal's long-term protection.In addition,the integration of wear-resistant materials further improves the durability of coatings under mechanical stress.The most recent research efforts have been directed towards the preparation of multifunctional composites,with an emphasis on nanomaterials,functional polymers,and state-of-the-art fabrication techniques in order to take advantage of their synergistic effects.Some of the methods that have so far exhibited promising potentials in fabricating these materials include the sol-gel method,layer-by-layer assembly,and plasma treatments.However,most of the fabricated products are still faced with significant challenges ranging from long-term stability to homogeneous adhesion of the coatings and their scalability for industrial applications.This review discusses the recent progress and the relationship between corrosion inhibition and self-healing efficiencies of wear resistant polymer nanocomposite coatings.Some challenges related to optimizing coating performance were also discussed.In addition,future directions ranging from the consideration of bioinspired designs,novel hybrid nanocomposite materials,and environmentally sustainable solutions integrated with smart protective coatings were also proposed as new wave technologies that can potentially revolutionize the corrosion protection offered by Mg alloys while opening up prospects for improved performance and sustainability.
基金supported by the National Natural Science Foundation of China(Nos.U21B2053,52071114,52001100,and 523B2010)Outstanding Youth Project of Natural Science Foundation of Heilongjiang Province(No.YQ2023E008)+1 种基金Young Elite Scientists Sponsorship Program by CAST(NO.2021QNRC001)Heilongjiang Touyan Team Program.
文摘Silicide coatings have proven to be promising for improving the high-temperature oxidation resistance of niobium alloy.However,the long-term protective property of single silicide coating remains a long-time endeavor due to the deficiency of oxygen-consuming phases,as well as the self-healing ability of the protective layer.Herein,a silicide-based composite coating is constructed on niobium alloy by incor-poration of nano-SiC particles for enhancing the high-temperature oxidation resistance.Isothermal oxi-dation results at 1250℃ for 50 h indicate that NbSi_(2)/Nb_(2)O_(5)-SiO_(2)/SiC multilayer coated sample with a low mass gain of 2.49 mg/cm^(2) shows an improved oxidation resistance compared with NbSi_(2) coating(6.49 mg/cm^(2)).The enhanced high-temperature antioxidant performance of NbSi_(2)/Nb_(2)O_(5)-SiO_(2)/SiC multi-layer coating is mainly attributed to the formation of the protective SiO_(2) self-healing film and the high-temperature diffusion behavior of NbSi_(2)/substrate.
基金supported by the National Natural Science Foundation of China(No.52001034)the China Postdoctoral Science Foundation(No.2023M731677)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_3032).
文摘Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates the preparation of ZnO-containing micro-arc oxidation coatings with dual functionality by incorporating nano-ZnO into MAO electrolyte.The influence of varying ZnO concentrations on the microstructure,corrosion resistance,and antibacterial properties of the coating was examined through microstructure analysis,immersion tests,electrochemical experiments,and antibacterial assays.The findings revealed that the addition of nano-ZnO significantly enhanced the corrosion resistance of the MAO-coated alloy.Specifically,when the ZnO concentration in the electrolyte was 5 g/L,the corrosion rate was more than ten times lower compared to the MAO coatings without ZnO.Moreover,the antibacterial efficacy of ZnO+MAO coating,prepared with a ZnO concentration of 5 g/L,surpassed 95%after 24 h of co-culturing with Staphylococcus aureus(S.aureus).The nano-ZnO+MAO-coated alloy exhibited exceptional degradation resistance,corrosion resistance,and antibacterial effectiveness.
基金supported by the Chongqing Natural Science Foundation(No.CSTB2023NSCQ-MSX0512)Municipal Human Resources and Social Security Bureau(No.cx2022098)China Postdoctoral Science Foundation(Nos.2022T150767 and 2021M693708).
文摘Mg and its alloys show high potential to be applied as implant materials due to their superior properties like biodegradability,bioactivity,biocompatibility,and suitable mechanical behaviors.Nevertheless,the fast and uncontrolled degradation of Mg alloys in biological environment severely restricts their wide applications as biomedical materials.In comparison with alloying,surface coatings can not only improve corrosion resistance but also impart other bio-functional properties to achieve diverse clinical requirements.This review analyzes and summarizes the most recent developments in popular coating technologies,including micro-arc oxidation,electrophoretic deposition,chemical conversion,anodic oxidation,layered double hydroxide,and sol-gel coatings.Considering inevitable damages under complex service conditions,smart self-healing coatings are also introduced in each coating technology.The existing issues and future perspectives are finally discussed to facilitate applications of Mg alloys as biomedical materials in the medical industry.
基金financial supports from Shanxi Provincial Natural Science Foundation,China(No.20210302123162)Shanxi Scholarship Council of China(No.2024-057)+2 种基金State Key Laboratory of Advanced Metal Materials,China(No.2019-ZD02)Science and Technology Achievement Transformation and Cultivation Project of Shanxi,China(No.2020CG011)Shanxi“1331 Project”Quality Improvement and Efficiency Project,China。
文摘A Cr/CoNiCrAlTaY bilayer coating was prepared on the Ti-45Al-8.5Nb alloy by plasma surface metallurgy technique.The as-prepared coating with a grain size of~2μm exhibited a dense microstructure and strong adhesion due to metallurgical bonding,consisting of outermost Cr layer and CoNiCrAlTaY transition layer.The typical power-law relationship between mass gain and time was obtained for the coated specimens with a rate exponent of 3.18 following oxidation at 1173 K.The top Cr_(2)O_(3)film and spinel oxides(i.e.,NiCr_(2)O_(4)and CoCr_(2)O_(4))exhibited a protective effect with a low oxidation reaction rate.Interfacial analysis identified Ta precipitates(Cr_(2)Ta and TaAl_(3))and Ta oxides(Ta_(2)O_(5)and Ta_(2)O_(3)),which played an essential role in retarding rapid diffusion and enhancing adhesion and oxidation resistance.
基金supported by the National Natural Science Foundation of China (No. 22008256)。
文摘Silicon is believed to be a critical anode material for approaching the roadmap of lithium-ion batteries due to its high specific capacity. But this aim has been hindered by the quick capacity fading of its electrodes during repeated charge–discharge cycles. In this work, a “soft-hard”double-layer coating has been proposed and carried out on ball-milled silicon particles. It is composed of inside conductive pathway and outside elastic coating, which is achieved by decomposing a conductive graphite layer on the silicon surface and further coating it with a polymer layer.The incorporation of the second elastic coating on the inside carbon coating enables silicon particles strongly interacted with binders, thereby making the electrodes displaying an obviously improved cycling stability. As-obtained double-coated silicon anodes deliver a reversible capacity of 2280 m Ah g^(-1)at the voltage of 0.05–2 V, and maintains over 1763 mAh g^(-1)after 50 cycles. The double-layer coating does not crack after the repeated cycling, critical for the robust performance of the electrodes. In addition, as-obtained silicon particles are mixed with commercial graphite to make actual anodes for lithium-ion batteries. A capacity of 714 mAh g^(-1)has been achieved based on the total mass of the electrodes containing 10 wt.% double-coated silicon particles. Compared with traditional carbon coating or polymeric coating, the double-coating electrodes display a much better performance. Therefore, the double-coating strategy can give inspiration for better design and synthesis of silicon anodes, as well as other battery materials.
