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
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
We synthesized tungsten-doped vanadium dioxide(W-VO_(2))particles via a one-step hydrothermal method,followed by their integration with antimony-doped tin oxide(ATO)nanoparticles to formulate a composite coating.Subse...We synthesized tungsten-doped vanadium dioxide(W-VO_(2))particles via a one-step hydrothermal method,followed by their integration with antimony-doped tin oxide(ATO)nanoparticles to formulate a composite coating.Subsequently,the VO_(2)/ATO composite coating was fabricated through a spin-coating process.The impact of varying W-VO_(2) content and coating thickness on the performance of the composite coatings was systematically investigated by employing X-ray diffraction,particle size distribution analysis,spectrometry,and other pertinent test methodologies.Our findings revealed that an escalation in both W-VO_(2) content and coating thickness retained high transmittance in the near-infrared band at lower temperatures.However,as the temperature increased,a notable reduction in transmittance in the near-infrared band was observed,alongside a slight decrease in transmittance within the visible band.Remarkably,when the W-VO_(2) content reached 5%and the coating thickness was 1253 nm,the transmittance of the composite coating surpassed 80%.Furthermore,the heat insulation effect achieved a remarkable 10.0℃increase.Consequently,the synthesized composite coating demonstrates significant potential for smart glass applications,particularly in the realm of heat-insulating glass.展开更多
Refractory metals and their alloys have excellent properties such as high-temperature strength and corrosion resistance.It is widely used in aerospace,electronics industry and other fields.However,refractory alloys ar...Refractory metals and their alloys have excellent properties such as high-temperature strength and corrosion resistance.It is widely used in aerospace,electronics industry and other fields.However,refractory alloys are prone to oxidation and failure in high-temperature service environments.The preparation of a MoSi_(2) antioxidant coating is an effective method for improving the protective ability of refractory metals at high temperatures.However,although MoSi_(2) coatings have many advantages,it is difficult to meet the increasingly stringent service requirements.To address these challenges,researchers have used different elements to modify a single MoSi_(2) coating and improve its overall oxidation resistance.In this study,the roles of one or more elements(Si,B,N,Zr,Al,W,Hf,Y,Ti and Cr)in MoSi_(2) coatings are systematically reviewed.Simultaneously,the mechanism of single or multiple synergistic modification of MoSi_(2) coatings with different elements was discussed.Finally,the development prospects of MoSi_(2) coating modification of refractory metals and their alloys are discussed.展开更多
Nanostructured Al_(2)O_(3)-10wt.%TiO_(2)-nCeO_(2)ceramic coatings(where n is 0 wt.%,0.2 wt.%,0.5 wt.%,and 0.8 wt.%)were prepared on a 304 stainless steel substrate using atmospheric plasma spraying.The phase compositi...Nanostructured Al_(2)O_(3)-10wt.%TiO_(2)-nCeO_(2)ceramic coatings(where n is 0 wt.%,0.2 wt.%,0.5 wt.%,and 0.8 wt.%)were prepared on a 304 stainless steel substrate using atmospheric plasma spraying.The phase composition and microstructure of the coatings were characterized using an X-ray diffractometer and a scanning electron microscope.The corrosion resistance of the coatings was as-sessed through electrochemical experiments and chloride ion corrosion tests.The results indicated that the coatings comprised both partially and fully melted regions,with spherical particles and pores present on the coating surfaces.The incorporation of CeO_(2)en-hanced the melting of the sprayed powder during the spraying process.When the CeO_(2)content was 0.2 wt.%,the melting of the sprayed powder was optimal.The porosity of the coating was minimized to 2.45%.CeO_(2)also positively influenced the grain refine-ment of the coating;at 0.2 wt.%CeO_(2),the grain size was at its minimum.The grain size of this coating was calculated to be 21.135 nm using the Scherrer formula.This coating demonstrated the best corrosion resistance,with a corrosion potential of-596.31 mV and a corrosion current density of 1.65×10^(-6)A/cm^(2),resulting in a weight loss of 0.0170 g due to chloride ion corrosion.展开更多
Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)u...Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)using one-step electrodeposition method is shown.The effect of processing parameters on surface structure and wettability was thoroughly explored,resulting in the identification of three typical surface morphologies.The prepared coating with petal-like structure(SSN-3)obtained under the optimum parameters exhibited the best water repellency,achieving a contact angle of 162.7°and a sliding angle of 4.1°.The droplet bouncing behavior on SSN coatings surface was studied,and the delayed icing time was recorded.Meanwhile,the mechanical stability and chemical corrosion resistance of SSN coatings were focused.The superhydrophobic SSN-3 coating with unique surface structure exhibited excellent reliability.The anticorrosion mechanism of SSN-3 coating was discussed,and its corrosion protection efficiency was up to 98.5%.The superior properties of the superhydrophobic SSN-3 coating make it suitable for diverse applications.展开更多
To investigate the mechanism by which ZrO_(2)modification affects the electrochemical performance of the NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)cathode material for sodium-ion batteries,ZrO_(2)-coated NFM(ZrO_(2)@NFM)was...To investigate the mechanism by which ZrO_(2)modification affects the electrochemical performance of the NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)cathode material for sodium-ion batteries,ZrO_(2)-coated NFM(ZrO_(2)@NFM)was prepared via high-temperature calcination.XRD refinement results revealed that ZrO_(2)modification increased the Na-layer spacing in the NFM material.XPS analysis results demonstrated that ZrO_(2)modification adjusted the Mn^(3+)/Mn^(4+)ratio in NFM by reducing the Mn^(3+)content.Electrochemical test results revealed that,compared to NFM,ZrO_(2)@NFM exhibited superior rate capability and cycling stability.It also exhibited significantly enhanced Na^(+)diffusion coefficients and reduced interfacial charge transfer resistance.The ZrO_(2)coating increased Na-layer spacing,reduced electrochemical polarization,and inhibited side reactions.In summary,the synergistic effect of component regulation and surface engineering through ZrO_(2)coating improved Na^(+)diffusion kinetics and enhanced cycling stability.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
To solve the problems of deformation,micro-cracks,and residual tensile stress in laser cladding coatings,the technique of laser cladding with Fe-based memory alloy can be considered.However,the process of in-situ synt...To solve the problems of deformation,micro-cracks,and residual tensile stress in laser cladding coatings,the technique of laser cladding with Fe-based memory alloy can be considered.However,the process of in-situ synthesis of Fe-based memory alloy coatings is extremely complex.At present,there is no clear guidance scheme for its preparation process,which limits its promotion and application to some extent.Therefore,in this study,response surface methodology(RSM)was used to model the response surface between the target values and the cladding process parameters.The NSGA-2 algorithm was employed to optimize the process parameters.The results indicate that the composite optimization method consisting of RSM and the NSGA-2 algorithm can establish a more accurate model,with an error of less than 4.5%between the predicted and actual values.Based on this established model,the optimal scheme for process parameters corresponding to different target results can be rapidly obtained.The prepared coating exhibits a uniform structure,with no defects such as pores,cracks,and deformation.The surface roughness and microhardness of the coating are enhanced,the shaping quality of the coating is effectively improved,and the electrochemical corrosion performance of the coating in 3.5%NaCl solution is obviously better than that of the substrate,providing an important guide for engineering applications.展开更多
Combining Mg and Al dissimilar metals further reduces structural weight,but the formation of intermetallic compounds(IMCs)affectsAl/Mg joint properties.To prevent IMCs,a Ni-Al_(2)O_(3)composite coating was pre-plated ...Combining Mg and Al dissimilar metals further reduces structural weight,but the formation of intermetallic compounds(IMCs)affectsAl/Mg joint properties.To prevent IMCs,a Ni-Al_(2)O_(3)composite coating was pre-plated on the Mg alloy substrate,and then Sn_(3.0)Ag_(0.5)Cu(SAC 305)solder was utilized to facilitate the joining of AZ31 Mg/6061 Al through ultrasonic-assisted soldering.We investigated the impactof Al_(2)O_(3)nano sol content in the coating on microstructure evolution,IMCs formation,and mechanical properties.Results indicated that theNi-Al_(2)O_(3)composite coating effectively suppressed the Mg-Sn reaction,thereby preventing the formation of Mg_(2)Sn IMC and significantlyenhancing joint strength.In joints with a Ni-Al_(2)O_(3)composite coating containing 50 mL/L Al_(2)O_(3)nano sol,no Mg_(2)Sn IMC was detectedafter 50 min of holding at 260℃,achieving a maximum shear strength of approximately 67.2 MPa.Increasing the Al_(2)O_(3)concentrationfurther expanded the soldering process window.For the joint with Ni-Al_(2)O_(3)(100 mL/L Al_(2)O_(3)nano sol)composite coating held at 260℃for 70 min,the coating was dissolved to a thickness of about 5.8μm,but no Mg_(2)Sn IMC was observed.The Ni-based solid solution formednear the coating/solder interface was strengthened,leading to fractures occurring within the SAC solder,and the maximum shear strengthfurther increased to 73.9 MPa.The strengthening mechanism of the joints facilitated by using the Ni-Al_(2)O_(3)composite coating was revealedby comparing with pure Ni-assisted joints.Therefore,employing a Ni-Al_(2)O_(3)composite coating as a barrier layer represents a promisingstrategy for inhibiting IMC formation during the joining of dissimilar metals.展开更多
The corrosion behavior of Ni-Co-CeO_(2) composite coating was investigated under a simulated high-temperature marine atmosphere alongside Ni-Co coating. The corrosion kinetics, phase composition and microstructure evo...The corrosion behavior of Ni-Co-CeO_(2) composite coating was investigated under a simulated high-temperature marine atmosphere alongside Ni-Co coating. The corrosion kinetics, phase composition and microstructure evolution of the coatings were analyzed. A multi-layered oxide scale formed due to the synergistic corrosion by H_(2)O and NaCl. The growth mechanism of the Co_(3)O_(4), Fe_(3)O_(4), Fe_(2)O3, CoFe_(2)O_(4), NiFe_(2)O_(4) and NiO in the scale was proposed according to the distribution of the CeO_(2) particles. Compared to Ni-Co cating, the Ni-Co-CeO_(2) coating exhibited superior corrosion resistance in the H_(2)O/NaCl steam, which is beacause the CeO_(2) exerted a blocking effect on retarding the diffusion of Fe atoms and corrosive medium, contributing to a reduced corrosion rate and an improved oxide adhesion compared to Ni-Co coating.展开更多
Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cath...Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cathode covered with an ultrathin ZrO_(2)layer was prepared through atomic layer deposition(ALD).It is found that the LNMO cathode deposited with 20 layers of ZrO_(2)(LNMOZ20)exhibits the best electrochemical performance,achieving a high discharge capacity of 117.1 mA·h/g,with a capacity retention of 87.4%after 600 cycles at a current density of 1C.Furthermore,even at higher current densities of 5C and 10C,the LNMOZ20 electrode still demonstrates excellent stability with discharge capacities reaching 111.7 and 103.6 mA·h/g,and capacity retentions maintaining at 81.0%and 101.4%after 2000 cycles,respectively.This study highlights that the incorporation of an ultrathin ZrO_(2)layer by ALD is an effective strategy for enhancing the long-term cycling stability of LNMO cathodes.展开更多
To satisfy the demands of modern society for high-energy–density sulfide-based all-solid-state lithium batteries(ASSLBs),Ni-rich cathode materials have gained much attention for their high capacity and energy density...To satisfy the demands of modern society for high-energy–density sulfide-based all-solid-state lithium batteries(ASSLBs),Ni-rich cathode materials have gained much attention for their high capacity and energy density.However,their practical deployment is hindered by accelerated interface degradation and capacity decay originating from surface oxygen release and lattice oxygen activation during prolonged cycling.In this study,Ti_(x)NbB_((1−x))C_(2)was successfully coated on the surface of LiNi_(0.94)Co_(0.05)Mn_(0.01)O_(2).Density functional theory(DFT)calculations first elucidate a“point-to-point”anchoring mechanism where each surface oxygen atom coordinates with single species(Ti/Nb/B)offered by Ti_(x)NbB_((1−x))C_(2),which forms robust O–M bonds and sustain a stable interface structure.The electron energy loss spectroscopy(EELS)reveals the segregation of Ti/Nb toward subsurface layers during cycling,creating an optimized lattice oxygen coordination environment and suppressing oxygen activation.The dual oxygen stabilization mechanism dramatically improves the reversibility of phase transition and the structural stability of the Ni-rich cathode materials.Moreover,Ti_(x)NbB_((1−x))C_(2)as the protective layer decreases mechanical strain and suppresses the parasitic reactions.Consequently,the engineered cathode delivers 91%capacity retention after 1000 cycles at 0.3 C,suggesting excellent cycling stability.The research delivers a new design philosophy for the coating layer that can stabilize surface oxygen.Furthermore,the atomistic understanding of the structure–property relationship of the Ni-rich cathode materials provides valuable guidance for the future design of new cathode materials with superior structural stability in ASSLBs.展开更多
To improve the oxidation resistance of carbon/carbon composites,ZrB2-MoSi2/SiC coating on the carbon/carbon substrate was prepared.The inner coating of SiC was prepared by pack cementation and the outer coating of ZrB...To improve the oxidation resistance of carbon/carbon composites,ZrB2-MoSi2/SiC coating on the carbon/carbon substrate was prepared.The inner coating of SiC was prepared by pack cementation and the outer coating of ZrB2-MoSi2 was prepared by slurry painting.The phase compositions and microstructures of the coating were characterized by XRD and SEM,respectively.The preparation and the high temperature oxidation property of the coated composites were investigated.The results show that the outer coating of carbon/carbon composites is composed of ZrB2,MoSi2 and SiC phases.The mass losses of the ZrB2-MoSi2/SiC coated samples with SiC nano-whiskers after 30 h and 10 h of oxidation at 1 273 K and 1 773 K were,respectively,5.3% and 3.0%.The ZrB2-MoSi2/SiC coated samples exhibit self-sealing performance and good oxidation resistance at high temperature.展开更多
To improve the oxidation resistance of carbon/carbon （C/C） composites in air at high temperatures, a SiC- MoSi2/ZrO2-MoSi2 coating was prepared on the surface of C/C composites by pack cementation and slurry method....To improve the oxidation resistance of carbon/carbon （C/C） composites in air at high temperatures, a SiC- MoSi2/ZrO2-MoSi2 coating was prepared on the surface of C/C composites by pack cementation and slurry method. The microstructures and phase compositions of the coated C/C composites were analyzed by scanning electron microscopy and X-ray diffraction, respectively. The result shows that the SiC-MoSi2/ZrO2-MoSi2 coating is dense and crack-free with a thickness of 250-300 μm. The preparation and the high temperature oxidation property of the coated composites were investigated. The as-received coating has excellent oxidation protection ability and can protect C/C composites from oxidation for 260 h at 1773 K in air. The excellent anti-oxidation performance of the coating is considered to come from the formation of ZrSiO4, which improves the stability of the coating at high temperatures.展开更多
To improve the anti-oxidation ability of silicon-based coating for carbon/carbon （C/C） composites at high temperatures, a ZrB2 modified silicon-based multilayer oxidation protective coating was prepared by pack ceme...To improve the anti-oxidation ability of silicon-based coating for carbon/carbon （C/C） composites at high temperatures, a ZrB2 modified silicon-based multilayer oxidation protective coating was prepared by pack cementation. The phase composition, microstructure and oxidation resistance at 1773, 1873 and 1953 K in air were investigated. The prepared coating exhibits dense structure and good oxidation protective ability. Due to the formation of stable ZrSiO4-SiO2 compound, the coating can effectively protect C/C composites from oxidation at 1773 K for more than 550 h. The anti-oxidation performance decreases with the increase of oxidation temperature. The mass loss of coated sample is 2.44% after oxidation at 1953 K for 50 h, which is attributed to the decomposition of ZrSiO4 and the volatilization of SiO2 protection layer.展开更多
A Cr/Cr2N/CrN multilayer coating with a thickness of 24.4 μm was deposited by multi-arc ion plating. The coating was systematically characterized by field emission scanning electron microscopy(FESEM), X-ray photoelec...A Cr/Cr2N/CrN multilayer coating with a thickness of 24.4 μm was deposited by multi-arc ion plating. The coating was systematically characterized by field emission scanning electron microscopy(FESEM), X-ray photoelectron spectrometry(XPS), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD) and transmission electron microscopy(TEM). Hardness and adhesion were tested by nanoindentation and scratch tester, respectively. The friction properties were investigated by a reciprocating UMT-3MT ball-on-disk tribometer in air and seawater. The results showed that the multilayer coating consisted of three different layers, with Cr,Cr2N and CrN phases, respectively. Compared with CrN single layer coating, the adhesion of the multilayer coating was improved significantly, the hardness of the multilayer coating was(21±2) GPa. The corrosion resistance of the multilayer coating was also improved in artificial seawater. The friction coefficient of multilayer coating was lower than that of CrN single layer coating both in air and seawater.展开更多
The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and trib...The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and tribological properties of the composite coatings were researched. The results show that the composite coatings mainly consist of γ-Ni, α-Al2O3, γ-Al2O3 and rutile-TiO2 etc, and exhibit lower friction coefficients and wear losses than the Ni-based alloy coatings at different loads and speeds. The composite coating bears low contact stress at 3 N and its wear mechanism is micro-cutting wear. As loads increase to 6-12 N, the contact stress is higher than the elastic limit stress of worn surface, and the wear mechanisms change into multi-plastic deformation wear, micro-brittle fracture wear and abrasive wear. With the increase of speeds, the contact temperature of worn surface increases. The composite coating experiences multi-plastic deformation wear, fatigue wear and adhesive wear.展开更多
In order to reduce the friction coefficients and improve the wear resistance of mechanical parts, which work in the severe friction and wear conditions at heavy loads, the graphite/CaFg/TiC/Ni-base alloy composite coa...In order to reduce the friction coefficients and improve the wear resistance of mechanical parts, which work in the severe friction and wear conditions at heavy loads, the graphite/CaFg/TiC/Ni-base alloy composite coatings were prepared by plasma spray and their tribological behavior and mechanisms were investigated. The results show that the friction coefficients of the composite coatings are in the range of 0.22-0.288, which are reduced by 25.9% to 53% compared with those of the pure Ni-base alloy coatings, and the wear rates of the former are 18.6%-70.1% less than those of the latter. When wear against GCr15 steel balls, a transferred layer mainly composed of ferric oxides, graphite and CaF2 may gradually develop on the worn surface of the composite coatings, which made the friction and wear between GCr15 steel ball and the composite coatings change into that between the former and the transferred layer. So the friction coefficients and the wear lubrication effect of the transferred layer. The main wear layer in friction process. rates of the composite coatings are greatly reduced because of the solid mechanism of the composite coatings is delamination of the transferred展开更多
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Funded by Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park(No.Z221100006722022)。
文摘We synthesized tungsten-doped vanadium dioxide(W-VO_(2))particles via a one-step hydrothermal method,followed by their integration with antimony-doped tin oxide(ATO)nanoparticles to formulate a composite coating.Subsequently,the VO_(2)/ATO composite coating was fabricated through a spin-coating process.The impact of varying W-VO_(2) content and coating thickness on the performance of the composite coatings was systematically investigated by employing X-ray diffraction,particle size distribution analysis,spectrometry,and other pertinent test methodologies.Our findings revealed that an escalation in both W-VO_(2) content and coating thickness retained high transmittance in the near-infrared band at lower temperatures.However,as the temperature increased,a notable reduction in transmittance in the near-infrared band was observed,alongside a slight decrease in transmittance within the visible band.Remarkably,when the W-VO_(2) content reached 5%and the coating thickness was 1253 nm,the transmittance of the composite coating surpassed 80%.Furthermore,the heat insulation effect achieved a remarkable 10.0℃increase.Consequently,the synthesized composite coating demonstrates significant potential for smart glass applications,particularly in the realm of heat-insulating glass.
基金supported by the National Natural Science Foundation of China(No.52374401 and 52404409)the Key R&D Plan of Shaanxi Province(Nos.2024QCYKXJ-116 and 2023JBGS-14)+3 种基金the Scientific and Technological Innovation Team Project of Shaanxi Innovation Capability Support Plan(No.2022TD-30)Xi’an Science and Technology Plan Project(No.2023JHGXRC-0020)the“Young Talent Support Project”of China Association for Science and Technology of China.The Natural Science Foundation of Shaanxi Provincial(No.2024JC-YBQN-0367)China Postdoctoral Science Foundation(2024MD753961).
文摘Refractory metals and their alloys have excellent properties such as high-temperature strength and corrosion resistance.It is widely used in aerospace,electronics industry and other fields.However,refractory alloys are prone to oxidation and failure in high-temperature service environments.The preparation of a MoSi_(2) antioxidant coating is an effective method for improving the protective ability of refractory metals at high temperatures.However,although MoSi_(2) coatings have many advantages,it is difficult to meet the increasingly stringent service requirements.To address these challenges,researchers have used different elements to modify a single MoSi_(2) coating and improve its overall oxidation resistance.In this study,the roles of one or more elements(Si,B,N,Zr,Al,W,Hf,Y,Ti and Cr)in MoSi_(2) coatings are systematically reviewed.Simultaneously,the mechanism of single or multiple synergistic modification of MoSi_(2) coatings with different elements was discussed.Finally,the development prospects of MoSi_(2) coating modification of refractory metals and their alloys are discussed.
基金supported by the National Natural Science Foundation of China(Grant No.52375387).
文摘Nanostructured Al_(2)O_(3)-10wt.%TiO_(2)-nCeO_(2)ceramic coatings(where n is 0 wt.%,0.2 wt.%,0.5 wt.%,and 0.8 wt.%)were prepared on a 304 stainless steel substrate using atmospheric plasma spraying.The phase composition and microstructure of the coatings were characterized using an X-ray diffractometer and a scanning electron microscope.The corrosion resistance of the coatings was as-sessed through electrochemical experiments and chloride ion corrosion tests.The results indicated that the coatings comprised both partially and fully melted regions,with spherical particles and pores present on the coating surfaces.The incorporation of CeO_(2)en-hanced the melting of the sprayed powder during the spraying process.When the CeO_(2)content was 0.2 wt.%,the melting of the sprayed powder was optimal.The porosity of the coating was minimized to 2.45%.CeO_(2)also positively influenced the grain refine-ment of the coating;at 0.2 wt.%CeO_(2),the grain size was at its minimum.The grain size of this coating was calculated to be 21.135 nm using the Scherrer formula.This coating demonstrated the best corrosion resistance,with a corrosion potential of-596.31 mV and a corrosion current density of 1.65×10^(-6)A/cm^(2),resulting in a weight loss of 0.0170 g due to chloride ion corrosion.
基金the Natural Science Foundation of Chongqing of China(Nos.CSTB2024NSCQ-MSX1013 and cstc2021jcyj-msxmX1139)the Science and Technology Research Program of Chongqing Education Commission(Nos.KJZD-K202304502,KJQN202201214,KJQN202001243 and KJZD-M202301201)the Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan province(No.2024CL05).
文摘Building a superhydrophobic coating on a carbon steel substrate is an effective strategy for enhancing metal protection.A practical approach to producing a series of superhydrophobic Ni/SiO_(2)composite coatings(SSN)using one-step electrodeposition method is shown.The effect of processing parameters on surface structure and wettability was thoroughly explored,resulting in the identification of three typical surface morphologies.The prepared coating with petal-like structure(SSN-3)obtained under the optimum parameters exhibited the best water repellency,achieving a contact angle of 162.7°and a sliding angle of 4.1°.The droplet bouncing behavior on SSN coatings surface was studied,and the delayed icing time was recorded.Meanwhile,the mechanical stability and chemical corrosion resistance of SSN coatings were focused.The superhydrophobic SSN-3 coating with unique surface structure exhibited excellent reliability.The anticorrosion mechanism of SSN-3 coating was discussed,and its corrosion protection efficiency was up to 98.5%.The superior properties of the superhydrophobic SSN-3 coating make it suitable for diverse applications.
基金supported by the Central South University Innovation-Driven Research Programme,China(No.2023CXQD053)the National Natural Science Foundation of China(No.52274310)financial support from the Government of Chongzuo,Guangxi Zhuang Autonomous Region,China(No.FA20210713).
文摘To investigate the mechanism by which ZrO_(2)modification affects the electrochemical performance of the NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM)cathode material for sodium-ion batteries,ZrO_(2)-coated NFM(ZrO_(2)@NFM)was prepared via high-temperature calcination.XRD refinement results revealed that ZrO_(2)modification increased the Na-layer spacing in the NFM material.XPS analysis results demonstrated that ZrO_(2)modification adjusted the Mn^(3+)/Mn^(4+)ratio in NFM by reducing the Mn^(3+)content.Electrochemical test results revealed that,compared to NFM,ZrO_(2)@NFM exhibited superior rate capability and cycling stability.It also exhibited significantly enhanced Na^(+)diffusion coefficients and reduced interfacial charge transfer resistance.The ZrO_(2)coating increased Na-layer spacing,reduced electrochemical polarization,and inhibited side reactions.In summary,the synergistic effect of component regulation and surface engineering through ZrO_(2)coating improved Na^(+)diffusion kinetics and enhanced cycling stability.
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financial supports from the National Natural Science Foundation of China-Youth Project(51801076)the Provincial Colleges and Universities Natural Science Research Project of Jiangsu Province(18KJB430009)+1 种基金the Postdoctoral Research Support Project of Jiangsu Province(1601055C)the Senior Talents Research Startup of Jiangsu University(14JDG126)。
文摘To solve the problems of deformation,micro-cracks,and residual tensile stress in laser cladding coatings,the technique of laser cladding with Fe-based memory alloy can be considered.However,the process of in-situ synthesis of Fe-based memory alloy coatings is extremely complex.At present,there is no clear guidance scheme for its preparation process,which limits its promotion and application to some extent.Therefore,in this study,response surface methodology(RSM)was used to model the response surface between the target values and the cladding process parameters.The NSGA-2 algorithm was employed to optimize the process parameters.The results indicate that the composite optimization method consisting of RSM and the NSGA-2 algorithm can establish a more accurate model,with an error of less than 4.5%between the predicted and actual values.Based on this established model,the optimal scheme for process parameters corresponding to different target results can be rapidly obtained.The prepared coating exhibits a uniform structure,with no defects such as pores,cracks,and deformation.The surface roughness and microhardness of the coating are enhanced,the shaping quality of the coating is effectively improved,and the electrochemical corrosion performance of the coating in 3.5%NaCl solution is obviously better than that of the substrate,providing an important guide for engineering applications.
基金support from the National Natural Science Foundation of China(grant numbers 52275385 and U2167216).
文摘Combining Mg and Al dissimilar metals further reduces structural weight,but the formation of intermetallic compounds(IMCs)affectsAl/Mg joint properties.To prevent IMCs,a Ni-Al_(2)O_(3)composite coating was pre-plated on the Mg alloy substrate,and then Sn_(3.0)Ag_(0.5)Cu(SAC 305)solder was utilized to facilitate the joining of AZ31 Mg/6061 Al through ultrasonic-assisted soldering.We investigated the impactof Al_(2)O_(3)nano sol content in the coating on microstructure evolution,IMCs formation,and mechanical properties.Results indicated that theNi-Al_(2)O_(3)composite coating effectively suppressed the Mg-Sn reaction,thereby preventing the formation of Mg_(2)Sn IMC and significantlyenhancing joint strength.In joints with a Ni-Al_(2)O_(3)composite coating containing 50 mL/L Al_(2)O_(3)nano sol,no Mg_(2)Sn IMC was detectedafter 50 min of holding at 260℃,achieving a maximum shear strength of approximately 67.2 MPa.Increasing the Al_(2)O_(3)concentrationfurther expanded the soldering process window.For the joint with Ni-Al_(2)O_(3)(100 mL/L Al_(2)O_(3)nano sol)composite coating held at 260℃for 70 min,the coating was dissolved to a thickness of about 5.8μm,but no Mg_(2)Sn IMC was observed.The Ni-based solid solution formednear the coating/solder interface was strengthened,leading to fractures occurring within the SAC solder,and the maximum shear strengthfurther increased to 73.9 MPa.The strengthening mechanism of the joints facilitated by using the Ni-Al_(2)O_(3)composite coating was revealedby comparing with pure Ni-assisted joints.Therefore,employing a Ni-Al_(2)O_(3)composite coating as a barrier layer represents a promisingstrategy for inhibiting IMC formation during the joining of dissimilar metals.
基金supported by the National Key Research and Development Programme(2023YFB3408200)the National Nature Science Foundation of China(52201076 and 52471077)+2 种基金the Guangdong Provincial Key R&D Programme(2023B0909020002)the Guangdong Basic and Applied Basic Research Foundation(2021A1515111065,2021B1515120014 and 2022A1515010934)the Fundamental Research Funds for the Central Universities(21623216 and 11623216).
文摘The corrosion behavior of Ni-Co-CeO_(2) composite coating was investigated under a simulated high-temperature marine atmosphere alongside Ni-Co coating. The corrosion kinetics, phase composition and microstructure evolution of the coatings were analyzed. A multi-layered oxide scale formed due to the synergistic corrosion by H_(2)O and NaCl. The growth mechanism of the Co_(3)O_(4), Fe_(3)O_(4), Fe_(2)O3, CoFe_(2)O_(4), NiFe_(2)O_(4) and NiO in the scale was proposed according to the distribution of the CeO_(2) particles. Compared to Ni-Co cating, the Ni-Co-CeO_(2) coating exhibited superior corrosion resistance in the H_(2)O/NaCl steam, which is beacause the CeO_(2) exerted a blocking effect on retarding the diffusion of Fe atoms and corrosive medium, contributing to a reduced corrosion rate and an improved oxide adhesion compared to Ni-Co coating.
基金supported by the National Natural Science Foundation of China(Nos.51931006,U22A20118).
文摘Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cathode covered with an ultrathin ZrO_(2)layer was prepared through atomic layer deposition(ALD).It is found that the LNMO cathode deposited with 20 layers of ZrO_(2)(LNMOZ20)exhibits the best electrochemical performance,achieving a high discharge capacity of 117.1 mA·h/g,with a capacity retention of 87.4%after 600 cycles at a current density of 1C.Furthermore,even at higher current densities of 5C and 10C,the LNMOZ20 electrode still demonstrates excellent stability with discharge capacities reaching 111.7 and 103.6 mA·h/g,and capacity retentions maintaining at 81.0%and 101.4%after 2000 cycles,respectively.This study highlights that the incorporation of an ultrathin ZrO_(2)layer by ALD is an effective strategy for enhancing the long-term cycling stability of LNMO cathodes.
基金supported by the National Natural Science Foundation of China(21203008,21975025,12274025,22372008,and 22179007)Hainan Province Science and Technology Special Fund(ZDYF2021SHFZ232 and ZDYF2023GXJS022)Hainan Province Postdoctoral Science Foundation(300333)。
文摘To satisfy the demands of modern society for high-energy–density sulfide-based all-solid-state lithium batteries(ASSLBs),Ni-rich cathode materials have gained much attention for their high capacity and energy density.However,their practical deployment is hindered by accelerated interface degradation and capacity decay originating from surface oxygen release and lattice oxygen activation during prolonged cycling.In this study,Ti_(x)NbB_((1−x))C_(2)was successfully coated on the surface of LiNi_(0.94)Co_(0.05)Mn_(0.01)O_(2).Density functional theory(DFT)calculations first elucidate a“point-to-point”anchoring mechanism where each surface oxygen atom coordinates with single species(Ti/Nb/B)offered by Ti_(x)NbB_((1−x))C_(2),which forms robust O–M bonds and sustain a stable interface structure.The electron energy loss spectroscopy(EELS)reveals the segregation of Ti/Nb toward subsurface layers during cycling,creating an optimized lattice oxygen coordination environment and suppressing oxygen activation.The dual oxygen stabilization mechanism dramatically improves the reversibility of phase transition and the structural stability of the Ni-rich cathode materials.Moreover,Ti_(x)NbB_((1−x))C_(2)as the protective layer decreases mechanical strain and suppresses the parasitic reactions.Consequently,the engineered cathode delivers 91%capacity retention after 1000 cycles at 0.3 C,suggesting excellent cycling stability.The research delivers a new design philosophy for the coating layer that can stabilize surface oxygen.Furthermore,the atomistic understanding of the structure–property relationship of the Ni-rich cathode materials provides valuable guidance for the future design of new cathode materials with superior structural stability in ASSLBs.
基金Project(50721003) supported by the Innovation Community Foundation of National Natural Science of ChinaProject(2011CB605805) supported by the National Basic Research Program of China
文摘To improve the oxidation resistance of carbon/carbon composites,ZrB2-MoSi2/SiC coating on the carbon/carbon substrate was prepared.The inner coating of SiC was prepared by pack cementation and the outer coating of ZrB2-MoSi2 was prepared by slurry painting.The phase compositions and microstructures of the coating were characterized by XRD and SEM,respectively.The preparation and the high temperature oxidation property of the coated composites were investigated.The results show that the outer coating of carbon/carbon composites is composed of ZrB2,MoSi2 and SiC phases.The mass losses of the ZrB2-MoSi2/SiC coated samples with SiC nano-whiskers after 30 h and 10 h of oxidation at 1 273 K and 1 773 K were,respectively,5.3% and 3.0%.The ZrB2-MoSi2/SiC coated samples exhibit self-sealing performance and good oxidation resistance at high temperature.
基金Projects(51221001,51222207)supported by the National Natural Science Foundation of ChinaProject(090677)supported by the Program for New Century Excellent Talents in University of ChinaProject(B08040)supported by Program of Introducing Talents of Discipline to Universities,China
文摘To improve the oxidation resistance of carbon/carbon （C/C） composites in air at high temperatures, a SiC- MoSi2/ZrO2-MoSi2 coating was prepared on the surface of C/C composites by pack cementation and slurry method. The microstructures and phase compositions of the coated C/C composites were analyzed by scanning electron microscopy and X-ray diffraction, respectively. The result shows that the SiC-MoSi2/ZrO2-MoSi2 coating is dense and crack-free with a thickness of 250-300 μm. The preparation and the high temperature oxidation property of the coated composites were investigated. The as-received coating has excellent oxidation protection ability and can protect C/C composites from oxidation for 260 h at 1773 K in air. The excellent anti-oxidation performance of the coating is considered to come from the formation of ZrSiO4, which improves the stability of the coating at high temperatures.
基金Projects(51221001,50972120)supported by the National Natural Science Foundation of ChinaProject(73-QP-2010)supported by the Research Fund of the State Key Laboratory of Solidification Processing of Northwestern Polytechnical University,ChinaProject(B08040)supported by Program of Introducing Talents of Discipline to Universities,China
文摘To improve the anti-oxidation ability of silicon-based coating for carbon/carbon （C/C） composites at high temperatures, a ZrB2 modified silicon-based multilayer oxidation protective coating was prepared by pack cementation. The phase composition, microstructure and oxidation resistance at 1773, 1873 and 1953 K in air were investigated. The prepared coating exhibits dense structure and good oxidation protective ability. Due to the formation of stable ZrSiO4-SiO2 compound, the coating can effectively protect C/C composites from oxidation at 1773 K for more than 550 h. The anti-oxidation performance decreases with the increase of oxidation temperature. The mass loss of coated sample is 2.44% after oxidation at 1953 K for 50 h, which is attributed to the decomposition of ZrSiO4 and the volatilization of SiO2 protection layer.
基金Project(51475449)supported by the National Natural Science Foundation of China
文摘A Cr/Cr2N/CrN multilayer coating with a thickness of 24.4 μm was deposited by multi-arc ion plating. The coating was systematically characterized by field emission scanning electron microscopy(FESEM), X-ray photoelectron spectrometry(XPS), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD) and transmission electron microscopy(TEM). Hardness and adhesion were tested by nanoindentation and scratch tester, respectively. The friction properties were investigated by a reciprocating UMT-3MT ball-on-disk tribometer in air and seawater. The results showed that the multilayer coating consisted of three different layers, with Cr,Cr2N and CrN phases, respectively. Compared with CrN single layer coating, the adhesion of the multilayer coating was improved significantly, the hardness of the multilayer coating was(21±2) GPa. The corrosion resistance of the multilayer coating was also improved in artificial seawater. The friction coefficient of multilayer coating was lower than that of CrN single layer coating both in air and seawater.
文摘The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and tribological properties of the composite coatings were researched. The results show that the composite coatings mainly consist of γ-Ni, α-Al2O3, γ-Al2O3 and rutile-TiO2 etc, and exhibit lower friction coefficients and wear losses than the Ni-based alloy coatings at different loads and speeds. The composite coating bears low contact stress at 3 N and its wear mechanism is micro-cutting wear. As loads increase to 6-12 N, the contact stress is higher than the elastic limit stress of worn surface, and the wear mechanisms change into multi-plastic deformation wear, micro-brittle fracture wear and abrasive wear. With the increase of speeds, the contact temperature of worn surface increases. The composite coating experiences multi-plastic deformation wear, fatigue wear and adhesive wear.
文摘In order to reduce the friction coefficients and improve the wear resistance of mechanical parts, which work in the severe friction and wear conditions at heavy loads, the graphite/CaFg/TiC/Ni-base alloy composite coatings were prepared by plasma spray and their tribological behavior and mechanisms were investigated. The results show that the friction coefficients of the composite coatings are in the range of 0.22-0.288, which are reduced by 25.9% to 53% compared with those of the pure Ni-base alloy coatings, and the wear rates of the former are 18.6%-70.1% less than those of the latter. When wear against GCr15 steel balls, a transferred layer mainly composed of ferric oxides, graphite and CaF2 may gradually develop on the worn surface of the composite coatings, which made the friction and wear between GCr15 steel ball and the composite coatings change into that between the former and the transferred layer. So the friction coefficients and the wear lubrication effect of the transferred layer. The main wear layer in friction process. rates of the composite coatings are greatly reduced because of the solid mechanism of the composite coatings is delamination of the transferred
