Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon ...Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.展开更多
Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatin...Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
This study presents the development of high-performance,solvent-free polyurethane-urea(PU)elastomeric coatings engineered for rapid curing and precise sprayability.Utilizing polyoxytetramethylene glycol(PTMG)as the pr...This study presents the development of high-performance,solvent-free polyurethane-urea(PU)elastomeric coatings engineered for rapid curing and precise sprayability.Utilizing polyoxytetramethylene glycol(PTMG)as the primary polyol and a static-mixing spraying technique,the formulations were systematically optimized.It was found that a soft-segment content of 64% yields optimalmechanical properties,achieving a remarkable tensile strength exceeding 30 MPa.Crucially,the incorporation of an ultra-low concentration(0.002 wt%)of dibutyltin dilaurate catalyst was sufficient to enhance curing completeness and mechanical performance while effectively eliminating moisture-induced foaming,a common challenge in solvent-free spray applications.The gel and tack-free times were successfully reduced to the order of minutes through strategic formulation with the chain extender dimethylsulfidetoluene diamine,minimizing reliance on high catalyst loadings.Theresultant PTMG-based coatings exhibit exceptional comprehensive properties,including a tensile strength>30 MPa,elongation at break>400%,and a tear strength of 66 N/mm,significantly surpassing conventional polypropylene-diamine-based polyurea systems.Furthermore,the coatings demonstrated superior low-temperature flexibility,evidenced by a glass transition temperature of-53℃,and suppressed soft-segment crystallinity.The solvent-free nature and tunable curing kinetics of this system enable precise spraying on complex geometries,effectively overcoming thickness-control limitations for small-object applications.This work establishes a sustainable and high-performance coating solution ideal for demanding impact-and corrosionresistant protective layers.展开更多
The efficient regulation of sunlight to minimize unnecessary energy exchange through windows plays a vital role in advancing building energy efficiency.However,the inferior stability of cerium-doped tungsten trioxide(...The efficient regulation of sunlight to minimize unnecessary energy exchange through windows plays a vital role in advancing building energy efficiency.However,the inferior stability of cerium-doped tungsten trioxide(CWO)as a near-infrared(NIR)shielding material,combined with the poor mechanical properties of its coatings,poses significant challenges for long-term thermal insulation performance.Here,a hierarchical thermal insulation coating with multifunctional integration has been developed.The inner layer’s excellent NIR shielding performance(94.4%)results in a temperature reduction of 13.6°C,demonstrating outstanding thermal insulation.Meanwhile,the external layer composed of polysilsesquioxane grafted by carboxylated hexafluoropropylene trimer offers exceptional weather resistance due to the low surface energy.The fluorosilicone coating effectively mitigates oxidation of CWO,as evidenced by the retention of NIR shielding performance even after 30 days of exposure to 60°C and 90%relative humidity.Furthermore,the coating demonstrates superior anti-graffiti properties and achieves an ultra-high mechanical strength of 0.49 GPa through precise fluorine content modulation.This hierarchical design integrates high hardness,excellent abrasion resistance,anti-graffiti functionality,transparency,and long-term operational durability into a single smart window system,offering a promising solution for reducing building energy consumption.展开更多
Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with co...Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with complex surfaces.Herein,by manipulating the interactions between block copolymers and selective solvents,we prepare repairable nanoporous polymers on arbitrary substrates.This is realized by an extremely simple sequential coating process:sequential coating of block copolymers and their swelling agents on substrate surfaces.The swelling agents are comprised of two solvents that swell the constituent blocks of the copolymers to different degrees,rapidly producing polymer coatings with uniform,interconnected,sub-50 nm pores.This sequential coating process is able to conformally build nanoporous polymers on nonplanar substrates with large lateral sizes and complex surface features,and also to in situ repair defects arising during usages.We further demonstrate that the nanoporous coatings show excellent antireflective and membrane separation performances.This sequential coating process is dictated by polymer–solvent interactions,and is expected to find applications in diverse fields for its simplicity,adaptability,and the capability to produce well-defined nanoporosities.展开更多
An advanced AlCrSiN/AlCrN/CrN/Cr multilayer coating was developed via hybrid multiarc ion plating and high-power impulse magnetron sputtering.The multilayer design enhanced the substrate-coating compatibility,achievin...An advanced AlCrSiN/AlCrN/CrN/Cr multilayer coating was developed via hybrid multiarc ion plating and high-power impulse magnetron sputtering.The multilayer design enhanced the substrate-coating compatibility,achieving a critical load of 87.8 N.Silicon doping induced nanocrystallization and amorphization,increasing the hardness to 26 GPa.At high temperatures,a nanoscale Cr-rich(Cr,Al)_(2)O_(3) layer was formed,effectively inhibiting oxygen diffusion.The coating underwent unique phase transformations,during which Cr_(2)N and amorphous Si3N4 were converted into dispersed SiCr_(3) nanoparticles,which stabilized Cr atoms and suppressed their outward diffusion.Ab initio molecular dynamics simulations revealed that Cr atoms exhibited higher chemical activity and oxygen-capture capability than Al atoms and Si atoms served as diffusion barriers by pinning onto the oxidized surface,considerably improving the oxidation resistance of the coating.展开更多
Epoxy resins are extensively employed in the construction,electronics,automotive,and aerospace industries owing to their outstandingmechanical strength,chemical resistance,and electrical insulation.However,their intri...Epoxy resins are extensively employed in the construction,electronics,automotive,and aerospace industries owing to their outstandingmechanical strength,chemical resistance,and electrical insulation.However,their intrinsic flammability,poor wear resistance,and hydrophilicity significantly restrict broader applications.To address these challenges,a novel multifunctional coating(CEOS-DOPO-PDMS)has been designed and fabricated via an NPGLIDE approach.The system integrates 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)as a reactive phosphorus-based flame retardant,epoxy-terminated polydimethylsiloxane(EP-PDMS)as a hydrophobic segment,and cycloaliphatic epoxy-functionalized oligosiloxanes(CEOS)as a cross-linking co-reactant.The resulting CEOSDOPO-PDMS hybrid precursor was blended with bisphenol A diglycidyl ether(DGEBA)in N-methyl-2-pyrrolidone(NMP)and subsequently cured to form epoxy-based NP-GLIDE coatings.The optimized coating exhibits superior integrated performance,including high hydrophobicity(water contact angle up to 109.6°),outstanding abrasion resistance(5H pencil hardness),and excellent flame retardancy(resisting combustion at 500℃ for 30 s).These enhancements originate from the cooperative effects of the Si-O-Si framework,low-surface-energy PDMS chains,and phosphorus-containing DOPOmoieties,which together provide stable thermal protection,surface roughness-induced hydrophobicity,and durable mechanical integrity.An effective strategy for constructing multifunctional epoxy-based coatingswith simultaneously enhanced flame retardancy,wear resistance,andwater repellency is presented.The CEOSDOPO-PDMS system holds great promise for advanced protective applications in construction,transportation,and aerospace engineering.展开更多
The high-temperature interaction of nanostructured Lu_(2)Si_(2)O_(7) environmental barrier coatings(EBCs)with calcium-magnesium-aluminosilicate(CMAS)was investigated at 1400℃ for 1,10,25,and 50 h to evaluate the coat...The high-temperature interaction of nanostructured Lu_(2)Si_(2)O_(7) environmental barrier coatings(EBCs)with calcium-magnesium-aluminosilicate(CMAS)was investigated at 1400℃ for 1,10,25,and 50 h to evaluate the coating’s resistance to CMAS corrosion.The results indicate a phase transformation over time,transitioning from Ca_(2)Lu_(8)(SiO_(4))6O_(2) apatite and Lu_(2)Si_(2)O_(7) to solely Lu_(2)Si_(2)O_(7).The interaction of the Lu_(2)Si_(2)O_(7) coating with the CMAS melts was divided into three stages based on the corrosion reaction behavior.The delamination cracks were distributed throughout the interface between the Si bond layer and Lu_(2)Si_(2)O_(7) layer after corroded at 1400℃ for 50 h,signifying coating failure.In addition,the influence of monosilicates,disilicates,and corrosion duration on the recession layer thickness was analyzed by comparing previous reports on RE_(2)SiO_(5)/RE_(2)Si_(2)O_(7) coatings(RE=Gd,Yb,Lu,Er).Furthermore,the variation in the thermally grown oxide layer thickness in CMAS-corroded Lu_(2)Si_(2)O_(7) coatings was systematically investigated.展开更多
Volatile organic compounds(VOCs)are a significant class of air contaminants,and their anthropogenic emissions in the environment are crucial for understanding and controlling VOC pollution and associated ozone formati...Volatile organic compounds(VOCs)are a significant class of air contaminants,and their anthropogenic emissions in the environment are crucial for understanding and controlling VOC pollution and associated ozone formation.Numerous studies have assessed VOC emissions from critical industrial sources in China,but understanding VOC emissions within the coating materials manufacturing industry remains limited.This study elucidates the characteristics of VOC emissions from the coating materials manufacturing industry through a comprehensive sector-based field sampling,constructs the emission source profiles,quantifies provincial-level VOC emissions,and evaluates the potential health risks to workers.According to experimental results,the main emissions from water-based coatings are oxygenated volatile organic compounds,which significantly contribute to ozone(O_(3))formation.The highest emissions from solvent-based coatings are aromatics.Health risk analysis revealed potential health impacts on workers in the workshop,indicating that solvent-based workshops posing a higher carcinogenic risk than water-based coating workshops.Strict control measures for fugitive emissions should be implemented to mitigate human health risks.Our results also demonstrate that the VOC emissions from coating materials manufacturing are mainly influenced by regional imbalances in coating production in China.Additionally,we explore the•OH and Cl•radical chemistry with ethyl acetate,revealing that Cl•is more likely to undergo H-abstraction reactions(HAA)than•OH.This study provides a source profile of the coating materials manufacturing industry and offers guidance on minimizing environmental impacts and promoting healthier working environments in the industry.展开更多
Towards the development of highly efficient electrochromic coatings,the crystallinity,morphology(e.g.size and shape)of electrochromic nanomaterials,and their charge insertion capacities play a significant role.Herein,...Towards the development of highly efficient electrochromic coatings,the crystallinity,morphology(e.g.size and shape)of electrochromic nanomaterials,and their charge insertion capacities play a significant role.Herein,we report the structure-dependent colouration effciency in electrochromic coatings based on the use of 0D,1D and 2D tungsten trioxide(WO_(3))nanostructures.A series of WO_(3)with different nanostructures were prepared and used as working electrodes to fabricate electrochromic devices for smart windows applications.Facile spray coating was applied on fluorine-doped tin oxide(FTO)substrate to make~70%transparent working electrodes to investigate their charge insertion capacities,electrochromic active surface area,and colouration efficiency.Results showed that the 2D WO_(3)nanoflakes displayed the highest diffusion coefficient for the intercalation of 1.52×10^(-10)cm^(2)/s with an increased electrochemical active surface area of 25.10 mF/cm^(2),a large modulation of optical reflectance(42.63%)with 3.79 s shorter response time for bleaching and a greater colouration efficiency(CE)value(89.29 cm^(2)/C)at 700 nm compared to the CE value for 1D WO_(3)(of 22 cm^(2)/C)and 0D WO_(3)(8 cm^(2)/C).The outcome of this study provides a new insight and valuable contribution to design an efficient electrochromic coating by controlling and optimising the nanostructures of selective electrochromic materials.展开更多
Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TB...Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TBCs was designed based on the coefficient of thermal expansion and the coating functionality,and it was completed using atmospheric plasma spraying technique.The microstructure,mechanical properties,and thermal properties were analyzed.Results indicate that the adhesion of the prepared dual-layer composite TBCs is excellent,and no noticeable cracks appear at the interface.Compared with the MoSi_(2)coating with a low fracture toughness(0.88 MPa·m^(1/2)),the Gd_(2)Zr_(2)O_(7)coating exhibits higher fracture toughness(1.74 MPa·m^(1/2))and stronger resistance to crack propagation.The prepared MoSi_(2)-Gd_(2)Zr_(2)O_(7)composite coatings have a high porosity(39%),low thermal conductivity(1.020 W·(m·K)^(−1),1200℃),and low thermal diffusivity(0.249 mm^(2)/s,1200℃).Additionally,they possess a high oxygen-vacancy concentration,which ensures excellent insulation performance.展开更多
The oxygen evolution reaction suffers from sluggish kinetics and poor structural stability,necessitating the development of nonprecious metal electrocatalysts with efficient electronic regulation and intrinsic structu...The oxygen evolution reaction suffers from sluggish kinetics and poor structural stability,necessitating the development of nonprecious metal electrocatalysts with efficient electronic regulation and intrinsic structural robustness.Herein,we construct a composite precatalyst of LaFe species modified cobalt carbonate hydroxide supported on nickel foam(LaFe–CoCH/NF)through a three-step process involving electrodeposition,hydrothermal growth,and co-deposition.This strategy enables the formation of a Ni–Co–Fe tri-level electron regulation pathway coupled with a spatially selective LaFe coating layer,achieving dual enhancement in both electronic modulation and structural stabilization.The hierarchical electron pathway effectively activates Ni sites within the nickel foam substrate,promotes the generation of high-valence Ni and Co species,and simultaneously suppresses the overoxidation of Fe.Meanwhile,the La-induced local electric field and buffering effect alleviate the detachment of the active phase during electrochemical reconstruction.As a result,the optimized LaFe–CoCH/NF catalyst exhibits outstanding oxygen evolution reaction performance,with a low Tafel slope of 33.75 mV dec-1 and exceptional durability,maintaining over 1500 h of stable operation at 10 mA cm^(-2),continuous operation for 1200 h at 50 and 100 mA cm^(-2),and more than 200 h of durability even at an ultrahigh current density of 500 mA cm^(-2).Mechanistic investigations reveal that the tri-metallic electron regulation strategy significantly improves interfacial charge transfer efficiency and structural integrity,offering theoretical guidance and a viable design route for advanced multi-metallic oxygen evolution reaction precatalysts.展开更多
Chlorite coats are believed to inhibit quartz cementation and preserve deeply-buried sandstone porosity.However,geologists face numerous challenges in evaluating the influences of chlorite coats in real cases.To tackl...Chlorite coats are believed to inhibit quartz cementation and preserve deeply-buried sandstone porosity.However,geologists face numerous challenges in evaluating the influences of chlorite coats in real cases.To tackle these challenges,this work reviewed a large number of case studies to discuss the proper way to evaluate their role using petrography.The following five main conclusions were drawn:(1)Compared to other coat parameters,coat coverage is more reliable in evaluating the influence of chlorite coats on quartz cements.(2)In addition to chlorite coats,quartz growth is influenced by multiple factors such as temperature,while sandstone porosity is affected by various factors including mechanical compaction;therefore,when evaluating the influence of chlorite coats,geologists should take these factors into account.(3)Even if no negative correlation exists between chlorite coats and quartz cements,and no positive correlation is observed between chlorite coats and sandstone porosity,one cannot simply conclude that chlorite coats do not inhibit quartz cements and protect sandstone porosity.(4)Chlorite coats can significantly occupy pore space,leading to a net porosity decrease.(5)Chlorite coats can undergo significantly dissolution,while whether this phenomenon is ubiquitous remains underexplored.展开更多
TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing Ti...TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.展开更多
As a representative insensitive high explosive,3-nitro-1,2,4-triazol-5-one(NTO)has garnered significant attention due to its ability to substantially reduce the risk of accidental detonation in munitions.However,its i...As a representative insensitive high explosive,3-nitro-1,2,4-triazol-5-one(NTO)has garnered significant attention due to its ability to substantially reduce the risk of accidental detonation in munitions.However,its inherent acidity induces severe interfacial corrosion of metal casings,thereby limiting its engineering applications.Based on the micro-corrosion mechanism of NTO on carbon steel(CS),this study designs an arginine-derived corrosion inhibitor,N2-[(phenylamino)thioxomethyl]-arginine(PTA).Electrochemical tests reveal that PTA exhibits an outstanding corrosion inhibition efficiency of 98.0%in NTO solution.Density functional theory(DFT)and molecular dynamics(MD)simulations elucidate the inhibition mechanism of PTA,demonstrating that it not only co-adsorbs with NTO^(−) onto the CS surface to form a dense and stable protective film but also disrupts the strong interactions between NTO^(−) and Fe,thereby suppressing nitro group-induced reduction,decomposition,and excessive surface oxidation.Furthermore,a PTA-loaded mesoporous silica(mSiO_(2))nanoparticles(NPs)-reinforced epoxy resin(EP)composite coating was constructed.Benefiting from the enhanced barrier properties of PTA@mSiO_(2) NPs and the synergistic effect between PTA and NTO^(−),the low-frequency impedance of the composite coating remained as high as 1.29×10^(9)Ω·cm^(2) after 30 days of immersion in NTO solution,exhibiting a two-order-of-magnitude improvement compared to the pure EP coating.This study proposes an effective corrosion control strategy to mitigate NTO-induced corrosion,providing insights into the development of advanced corrosion protection strategies for broader applications.展开更多
When micro/nano-scale gradient coatings are subject to large thermal gradients or high heat fluxes,the spatial size effect cannot be ignored.It is important to understand how the size effect influences the thermal fra...When micro/nano-scale gradient coatings are subject to large thermal gradients or high heat fluxes,the spatial size effect cannot be ignored.It is important to understand how the size effect influences the thermal fracture behavior of functionally graded coating/substrate structures.This study aims at analyzing the transient thermal fracture behavior of collinear interface cracks in functionally graded coating/substrate structures based on the nonlocal dual-phase-lag heat conduction model.By means of integral transform techniques,the mixed boundary problem is transformed into a set of singular integral equations,which are solved by the Chebyshev polynomials.The effects of the nonlocal parameter,coating thickness,crack spacing,and non-homogeneous parameters on the temperature and stress intensity factors(SIFs)are examined.The numerical results show that these parameters play an essential role in controlling the thermal fracture behavior of the structures,especially at micro/nano-scales.展开更多
Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrate...Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrates.In these coatings,a reactive emulsifier containing phosphate groups can be integrated into the molecular chain during polymerization,which enhances the coating's compactness and corrosion resistance.This work focuses on the synthesis of styrene-butyl acrylate(St-BA)latex and methyl methacrylate-butyl acrylate(MMA-BA)latex using the reactive phosphate emulsifier ANPEO_(10)-P_(1) through seed emulsion polymerization,achieving a conversion rate of approximately 99%and a solid content close to 50%.The resulting coatings from St-BA and MMA-BA latexes demonstrated long-term corrosion protection for carbon steel and aluminum alloy due to in-situ phosphatization,effectively preventing flash rust.Notably,the MMA-BA coating exhibited remarkable durability,enduring immersion for up to 1224 h(51 d)on Q 235 carbon steel before reaching the failure threshold(|Z|0.01 Hz£106Ω·cm^(2))on Q 235 carbon steel.On 5052 aluminum alloy,the St-BA coating maintained|Z|0.01 Hz>10^(8)Ω·cm^(2) for 480 h(20 d).Furthermore,the corrosion resistance of St-BA and MMA BA coatings on Q 235 steel sheet and 5052 aluminum alloy surpassed that of commercially available MMA-BA and St BA coatings after immersion in a 3.5 wt%NaCl aqueous solution.This work also delves into the anticorrosion mechanism of MMA-BA and St-BA coatings.展开更多
The Sn−2Al filler metal was utilized to bond W90 tungsten heavy alloys by the ultrasonic-assisted coating technology in atmospheric environment at 250℃.The effects of ultrasonic power and ultrasonic time on microstru...The Sn−2Al filler metal was utilized to bond W90 tungsten heavy alloys by the ultrasonic-assisted coating technology in atmospheric environment at 250℃.The effects of ultrasonic power and ultrasonic time on microstructure and interfacial strength of Sn−2Al/W90 interface were investigated.The ultrasound improved the wettability of Sn−2Al filler metal on W90 surface.As the ultrasonic power increased and ultrasonic time increased,the size of Al phase in seam decreased.The maximum value of Sn−2Al/W90 interfacial strength reached 30.1 MPa.Based on the acoustic pressure simulation and bubble dynamics,the intensity of cavitation effect was proportional to ultrasonic power.The generated high temperature and high pressure by cavitation effect reached 83799.6 K and 1.26×10^(14) Pa,respectively.展开更多
文摘Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.
基金National Natural Science Foundation of China(52272075,52472053)Research Fund of Youth Innovation Promotion Association of CAS,China(2021190)Defense Industrial Technology Development Program(JCKY2021130B007)。
文摘Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.
基金National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
基金funded by the National Natural Science Foundation of China(No.U2330207)the presidential foundation of China Academy of Engineering Physics(No.YZJJZQ2024004).
文摘This study presents the development of high-performance,solvent-free polyurethane-urea(PU)elastomeric coatings engineered for rapid curing and precise sprayability.Utilizing polyoxytetramethylene glycol(PTMG)as the primary polyol and a static-mixing spraying technique,the formulations were systematically optimized.It was found that a soft-segment content of 64% yields optimalmechanical properties,achieving a remarkable tensile strength exceeding 30 MPa.Crucially,the incorporation of an ultra-low concentration(0.002 wt%)of dibutyltin dilaurate catalyst was sufficient to enhance curing completeness and mechanical performance while effectively eliminating moisture-induced foaming,a common challenge in solvent-free spray applications.The gel and tack-free times were successfully reduced to the order of minutes through strategic formulation with the chain extender dimethylsulfidetoluene diamine,minimizing reliance on high catalyst loadings.Theresultant PTMG-based coatings exhibit exceptional comprehensive properties,including a tensile strength>30 MPa,elongation at break>400%,and a tear strength of 66 N/mm,significantly surpassing conventional polypropylene-diamine-based polyurea systems.Furthermore,the coatings demonstrated superior low-temperature flexibility,evidenced by a glass transition temperature of-53℃,and suppressed soft-segment crystallinity.The solvent-free nature and tunable curing kinetics of this system enable precise spraying on complex geometries,effectively overcoming thickness-control limitations for small-object applications.This work establishes a sustainable and high-performance coating solution ideal for demanding impact-and corrosionresistant protective layers.
基金financially supported by Shandong Province Postdoctoral Innovation Project(No.SDCX-ZG-202302017)Natural Science Foundation of Shandong Province(Nos.ZR2022QB045,ZR2024QB019 and ZR2025QC564).
文摘The efficient regulation of sunlight to minimize unnecessary energy exchange through windows plays a vital role in advancing building energy efficiency.However,the inferior stability of cerium-doped tungsten trioxide(CWO)as a near-infrared(NIR)shielding material,combined with the poor mechanical properties of its coatings,poses significant challenges for long-term thermal insulation performance.Here,a hierarchical thermal insulation coating with multifunctional integration has been developed.The inner layer’s excellent NIR shielding performance(94.4%)results in a temperature reduction of 13.6°C,demonstrating outstanding thermal insulation.Meanwhile,the external layer composed of polysilsesquioxane grafted by carboxylated hexafluoropropylene trimer offers exceptional weather resistance due to the low surface energy.The fluorosilicone coating effectively mitigates oxidation of CWO,as evidenced by the retention of NIR shielding performance even after 30 days of exposure to 60°C and 90%relative humidity.Furthermore,the coating demonstrates superior anti-graffiti properties and achieves an ultra-high mechanical strength of 0.49 GPa through precise fluorine content modulation.This hierarchical design integrates high hardness,excellent abrasion resistance,anti-graffiti functionality,transparency,and long-term operational durability into a single smart window system,offering a promising solution for reducing building energy consumption.
基金support from National Science Foundation of China(22438005)the Natural Science Foundation of Jiangsu Province(BE2022056-3)is gratefully acknowledged.
文摘Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with complex surfaces.Herein,by manipulating the interactions between block copolymers and selective solvents,we prepare repairable nanoporous polymers on arbitrary substrates.This is realized by an extremely simple sequential coating process:sequential coating of block copolymers and their swelling agents on substrate surfaces.The swelling agents are comprised of two solvents that swell the constituent blocks of the copolymers to different degrees,rapidly producing polymer coatings with uniform,interconnected,sub-50 nm pores.This sequential coating process is able to conformally build nanoporous polymers on nonplanar substrates with large lateral sizes and complex surface features,and also to in situ repair defects arising during usages.We further demonstrate that the nanoporous coatings show excellent antireflective and membrane separation performances.This sequential coating process is dictated by polymer–solvent interactions,and is expected to find applications in diverse fields for its simplicity,adaptability,and the capability to produce well-defined nanoporosities.
基金financially supported by the National Science and Technology Major Project(No.2024ZD1404705)。
文摘An advanced AlCrSiN/AlCrN/CrN/Cr multilayer coating was developed via hybrid multiarc ion plating and high-power impulse magnetron sputtering.The multilayer design enhanced the substrate-coating compatibility,achieving a critical load of 87.8 N.Silicon doping induced nanocrystallization and amorphization,increasing the hardness to 26 GPa.At high temperatures,a nanoscale Cr-rich(Cr,Al)_(2)O_(3) layer was formed,effectively inhibiting oxygen diffusion.The coating underwent unique phase transformations,during which Cr_(2)N and amorphous Si3N4 were converted into dispersed SiCr_(3) nanoparticles,which stabilized Cr atoms and suppressed their outward diffusion.Ab initio molecular dynamics simulations revealed that Cr atoms exhibited higher chemical activity and oxygen-capture capability than Al atoms and Si atoms served as diffusion barriers by pinning onto the oxidized surface,considerably improving the oxidation resistance of the coating.
基金supported by the Undergraduate Training Programs for Innovations by NEFU(grant number 202410225370)funded by Large-Scale Instrument and Equipment Sharing Service Platform of College of Chemistry,Chemical Engineering and Resource Utilization,NEFU.
文摘Epoxy resins are extensively employed in the construction,electronics,automotive,and aerospace industries owing to their outstandingmechanical strength,chemical resistance,and electrical insulation.However,their intrinsic flammability,poor wear resistance,and hydrophilicity significantly restrict broader applications.To address these challenges,a novel multifunctional coating(CEOS-DOPO-PDMS)has been designed and fabricated via an NPGLIDE approach.The system integrates 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)as a reactive phosphorus-based flame retardant,epoxy-terminated polydimethylsiloxane(EP-PDMS)as a hydrophobic segment,and cycloaliphatic epoxy-functionalized oligosiloxanes(CEOS)as a cross-linking co-reactant.The resulting CEOSDOPO-PDMS hybrid precursor was blended with bisphenol A diglycidyl ether(DGEBA)in N-methyl-2-pyrrolidone(NMP)and subsequently cured to form epoxy-based NP-GLIDE coatings.The optimized coating exhibits superior integrated performance,including high hydrophobicity(water contact angle up to 109.6°),outstanding abrasion resistance(5H pencil hardness),and excellent flame retardancy(resisting combustion at 500℃ for 30 s).These enhancements originate from the cooperative effects of the Si-O-Si framework,low-surface-energy PDMS chains,and phosphorus-containing DOPOmoieties,which together provide stable thermal protection,surface roughness-induced hydrophobicity,and durable mechanical integrity.An effective strategy for constructing multifunctional epoxy-based coatingswith simultaneously enhanced flame retardancy,wear resistance,andwater repellency is presented.The CEOSDOPO-PDMS system holds great promise for advanced protective applications in construction,transportation,and aerospace engineering.
基金supported by the National Science and Technology Major Project of China(No.2017-VI-0020-0093).
文摘The high-temperature interaction of nanostructured Lu_(2)Si_(2)O_(7) environmental barrier coatings(EBCs)with calcium-magnesium-aluminosilicate(CMAS)was investigated at 1400℃ for 1,10,25,and 50 h to evaluate the coating’s resistance to CMAS corrosion.The results indicate a phase transformation over time,transitioning from Ca_(2)Lu_(8)(SiO_(4))6O_(2) apatite and Lu_(2)Si_(2)O_(7) to solely Lu_(2)Si_(2)O_(7).The interaction of the Lu_(2)Si_(2)O_(7) coating with the CMAS melts was divided into three stages based on the corrosion reaction behavior.The delamination cracks were distributed throughout the interface between the Si bond layer and Lu_(2)Si_(2)O_(7) layer after corroded at 1400℃ for 50 h,signifying coating failure.In addition,the influence of monosilicates,disilicates,and corrosion duration on the recession layer thickness was analyzed by comparing previous reports on RE_(2)SiO_(5)/RE_(2)Si_(2)O_(7) coatings(RE=Gd,Yb,Lu,Er).Furthermore,the variation in the thermally grown oxide layer thickness in CMAS-corroded Lu_(2)Si_(2)O_(7) coatings was systematically investigated.
基金supported by the Key Research and Development Project of Shandong Province(No.2020CXGC011402)Taishan Scholars(No.ts201712003).
文摘Volatile organic compounds(VOCs)are a significant class of air contaminants,and their anthropogenic emissions in the environment are crucial for understanding and controlling VOC pollution and associated ozone formation.Numerous studies have assessed VOC emissions from critical industrial sources in China,but understanding VOC emissions within the coating materials manufacturing industry remains limited.This study elucidates the characteristics of VOC emissions from the coating materials manufacturing industry through a comprehensive sector-based field sampling,constructs the emission source profiles,quantifies provincial-level VOC emissions,and evaluates the potential health risks to workers.According to experimental results,the main emissions from water-based coatings are oxygenated volatile organic compounds,which significantly contribute to ozone(O_(3))formation.The highest emissions from solvent-based coatings are aromatics.Health risk analysis revealed potential health impacts on workers in the workshop,indicating that solvent-based workshops posing a higher carcinogenic risk than water-based coating workshops.Strict control measures for fugitive emissions should be implemented to mitigate human health risks.Our results also demonstrate that the VOC emissions from coating materials manufacturing are mainly influenced by regional imbalances in coating production in China.Additionally,we explore the•OH and Cl•radical chemistry with ethyl acetate,revealing that Cl•is more likely to undergo H-abstraction reactions(HAA)than•OH.This study provides a source profile of the coating materials manufacturing industry and offers guidance on minimizing environmental impacts and promoting healthier working environments in the industry.
基金the funding by the ARC Research Hub for Advanced Manufacturing with 2D Materials(ARC IH210100025)。
文摘Towards the development of highly efficient electrochromic coatings,the crystallinity,morphology(e.g.size and shape)of electrochromic nanomaterials,and their charge insertion capacities play a significant role.Herein,we report the structure-dependent colouration effciency in electrochromic coatings based on the use of 0D,1D and 2D tungsten trioxide(WO_(3))nanostructures.A series of WO_(3)with different nanostructures were prepared and used as working electrodes to fabricate electrochromic devices for smart windows applications.Facile spray coating was applied on fluorine-doped tin oxide(FTO)substrate to make~70%transparent working electrodes to investigate their charge insertion capacities,electrochromic active surface area,and colouration efficiency.Results showed that the 2D WO_(3)nanoflakes displayed the highest diffusion coefficient for the intercalation of 1.52×10^(-10)cm^(2)/s with an increased electrochemical active surface area of 25.10 mF/cm^(2),a large modulation of optical reflectance(42.63%)with 3.79 s shorter response time for bleaching and a greater colouration efficiency(CE)value(89.29 cm^(2)/C)at 700 nm compared to the CE value for 1D WO_(3)(of 22 cm^(2)/C)and 0D WO_(3)(8 cm^(2)/C).The outcome of this study provides a new insight and valuable contribution to design an efficient electrochromic coating by controlling and optimising the nanostructures of selective electrochromic materials.
基金Supported by Scientific and Technological Innovation of Shaanxi Provincial State-Owned Capital Operation Budget(2022-056)Institute's Self-Developed Technology Program(0801YK2317)+4 种基金Qin Chuangyuan Cites High-Level Innovation and Entrepreneurship Talent Program(QCYRCXM-2023-120)Qin Chuangyuan Industry Cluster Zone“Four Chains”Integration Program(2024CY-JJQ-46)National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘Dual-layer thermal barrier coatings(TBCs)with ultrahigh temperature resistance were prepared on the surface of molybdenum-rhenium alloy hot-end components.The preparation of the MoSi_(2)-Gd_(2)Zr_(2)O_(7)dual-layer TBCs was designed based on the coefficient of thermal expansion and the coating functionality,and it was completed using atmospheric plasma spraying technique.The microstructure,mechanical properties,and thermal properties were analyzed.Results indicate that the adhesion of the prepared dual-layer composite TBCs is excellent,and no noticeable cracks appear at the interface.Compared with the MoSi_(2)coating with a low fracture toughness(0.88 MPa·m^(1/2)),the Gd_(2)Zr_(2)O_(7)coating exhibits higher fracture toughness(1.74 MPa·m^(1/2))and stronger resistance to crack propagation.The prepared MoSi_(2)-Gd_(2)Zr_(2)O_(7)composite coatings have a high porosity(39%),low thermal conductivity(1.020 W·(m·K)^(−1),1200℃),and low thermal diffusivity(0.249 mm^(2)/s,1200℃).Additionally,they possess a high oxygen-vacancy concentration,which ensures excellent insulation performance.
文摘The oxygen evolution reaction suffers from sluggish kinetics and poor structural stability,necessitating the development of nonprecious metal electrocatalysts with efficient electronic regulation and intrinsic structural robustness.Herein,we construct a composite precatalyst of LaFe species modified cobalt carbonate hydroxide supported on nickel foam(LaFe–CoCH/NF)through a three-step process involving electrodeposition,hydrothermal growth,and co-deposition.This strategy enables the formation of a Ni–Co–Fe tri-level electron regulation pathway coupled with a spatially selective LaFe coating layer,achieving dual enhancement in both electronic modulation and structural stabilization.The hierarchical electron pathway effectively activates Ni sites within the nickel foam substrate,promotes the generation of high-valence Ni and Co species,and simultaneously suppresses the overoxidation of Fe.Meanwhile,the La-induced local electric field and buffering effect alleviate the detachment of the active phase during electrochemical reconstruction.As a result,the optimized LaFe–CoCH/NF catalyst exhibits outstanding oxygen evolution reaction performance,with a low Tafel slope of 33.75 mV dec-1 and exceptional durability,maintaining over 1500 h of stable operation at 10 mA cm^(-2),continuous operation for 1200 h at 50 and 100 mA cm^(-2),and more than 200 h of durability even at an ultrahigh current density of 500 mA cm^(-2).Mechanistic investigations reveal that the tri-metallic electron regulation strategy significantly improves interfacial charge transfer efficiency and structural integrity,offering theoretical guidance and a viable design route for advanced multi-metallic oxygen evolution reaction precatalysts.
基金financially supported by the Hubei Provincial 100-Talent Program 2025National Natural Science Foundation of China(No.42502111)+2 种基金National Postdoctoral Researchers Program(No.GZC20250293)China Postdoctoral Science Foundation(No.2025M770446)Melbourne Research Scholarship(No.396349)。
文摘Chlorite coats are believed to inhibit quartz cementation and preserve deeply-buried sandstone porosity.However,geologists face numerous challenges in evaluating the influences of chlorite coats in real cases.To tackle these challenges,this work reviewed a large number of case studies to discuss the proper way to evaluate their role using petrography.The following five main conclusions were drawn:(1)Compared to other coat parameters,coat coverage is more reliable in evaluating the influence of chlorite coats on quartz cements.(2)In addition to chlorite coats,quartz growth is influenced by multiple factors such as temperature,while sandstone porosity is affected by various factors including mechanical compaction;therefore,when evaluating the influence of chlorite coats,geologists should take these factors into account.(3)Even if no negative correlation exists between chlorite coats and quartz cements,and no positive correlation is observed between chlorite coats and sandstone porosity,one cannot simply conclude that chlorite coats do not inhibit quartz cements and protect sandstone porosity.(4)Chlorite coats can significantly occupy pore space,leading to a net porosity decrease.(5)Chlorite coats can undergo significantly dissolution,while whether this phenomenon is ubiquitous remains underexplored.
基金supported by the Original Exploratory Program of the National Natural Science Foundation of China(No.52450012)。
文摘TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.
文摘As a representative insensitive high explosive,3-nitro-1,2,4-triazol-5-one(NTO)has garnered significant attention due to its ability to substantially reduce the risk of accidental detonation in munitions.However,its inherent acidity induces severe interfacial corrosion of metal casings,thereby limiting its engineering applications.Based on the micro-corrosion mechanism of NTO on carbon steel(CS),this study designs an arginine-derived corrosion inhibitor,N2-[(phenylamino)thioxomethyl]-arginine(PTA).Electrochemical tests reveal that PTA exhibits an outstanding corrosion inhibition efficiency of 98.0%in NTO solution.Density functional theory(DFT)and molecular dynamics(MD)simulations elucidate the inhibition mechanism of PTA,demonstrating that it not only co-adsorbs with NTO^(−) onto the CS surface to form a dense and stable protective film but also disrupts the strong interactions between NTO^(−) and Fe,thereby suppressing nitro group-induced reduction,decomposition,and excessive surface oxidation.Furthermore,a PTA-loaded mesoporous silica(mSiO_(2))nanoparticles(NPs)-reinforced epoxy resin(EP)composite coating was constructed.Benefiting from the enhanced barrier properties of PTA@mSiO_(2) NPs and the synergistic effect between PTA and NTO^(−),the low-frequency impedance of the composite coating remained as high as 1.29×10^(9)Ω·cm^(2) after 30 days of immersion in NTO solution,exhibiting a two-order-of-magnitude improvement compared to the pure EP coating.This study proposes an effective corrosion control strategy to mitigate NTO-induced corrosion,providing insights into the development of advanced corrosion protection strategies for broader applications.
基金Project supported by the Natural Science Foundation of Shandong Province of China(No.ZR2024MA085)the Fundamental Research Funds for Central Universities of China(No.27RA2515008)。
文摘When micro/nano-scale gradient coatings are subject to large thermal gradients or high heat fluxes,the spatial size effect cannot be ignored.It is important to understand how the size effect influences the thermal fracture behavior of functionally graded coating/substrate structures.This study aims at analyzing the transient thermal fracture behavior of collinear interface cracks in functionally graded coating/substrate structures based on the nonlocal dual-phase-lag heat conduction model.By means of integral transform techniques,the mixed boundary problem is transformed into a set of singular integral equations,which are solved by the Chebyshev polynomials.The effects of the nonlocal parameter,coating thickness,crack spacing,and non-homogeneous parameters on the temperature and stress intensity factors(SIFs)are examined.The numerical results show that these parameters play an essential role in controlling the thermal fracture behavior of the structures,especially at micro/nano-scales.
基金Project(52373065)supported by the National Natural Science Foundation of ChinaProject(2220004002898)supported by the Zhuhai Industry University Research Cooperation and Basic and Applied Research Projects,China。
文摘Waterborne acrylic coatings are widely utilized due to their cost-effectiveness,high transparency,strong resistance to weather and chemicals,impressive mechanical properties,and excellent adhesion to various substrates.In these coatings,a reactive emulsifier containing phosphate groups can be integrated into the molecular chain during polymerization,which enhances the coating's compactness and corrosion resistance.This work focuses on the synthesis of styrene-butyl acrylate(St-BA)latex and methyl methacrylate-butyl acrylate(MMA-BA)latex using the reactive phosphate emulsifier ANPEO_(10)-P_(1) through seed emulsion polymerization,achieving a conversion rate of approximately 99%and a solid content close to 50%.The resulting coatings from St-BA and MMA-BA latexes demonstrated long-term corrosion protection for carbon steel and aluminum alloy due to in-situ phosphatization,effectively preventing flash rust.Notably,the MMA-BA coating exhibited remarkable durability,enduring immersion for up to 1224 h(51 d)on Q 235 carbon steel before reaching the failure threshold(|Z|0.01 Hz£106Ω·cm^(2))on Q 235 carbon steel.On 5052 aluminum alloy,the St-BA coating maintained|Z|0.01 Hz>10^(8)Ω·cm^(2) for 480 h(20 d).Furthermore,the corrosion resistance of St-BA and MMA BA coatings on Q 235 steel sheet and 5052 aluminum alloy surpassed that of commercially available MMA-BA and St BA coatings after immersion in a 3.5 wt%NaCl aqueous solution.This work also delves into the anticorrosion mechanism of MMA-BA and St-BA coatings.
基金supported by the National Natural Science Foundation of China(Nos.52105330,52175307)the Natural Science Foundation of Shandong Province,China(No.ZR2023JQ021)。
文摘The Sn−2Al filler metal was utilized to bond W90 tungsten heavy alloys by the ultrasonic-assisted coating technology in atmospheric environment at 250℃.The effects of ultrasonic power and ultrasonic time on microstructure and interfacial strength of Sn−2Al/W90 interface were investigated.The ultrasound improved the wettability of Sn−2Al filler metal on W90 surface.As the ultrasonic power increased and ultrasonic time increased,the size of Al phase in seam decreased.The maximum value of Sn−2Al/W90 interfacial strength reached 30.1 MPa.Based on the acoustic pressure simulation and bubble dynamics,the intensity of cavitation effect was proportional to ultrasonic power.The generated high temperature and high pressure by cavitation effect reached 83799.6 K and 1.26×10^(14) Pa,respectively.
