Magnesium alloys are lightweight materials with great potential,and plasma electrolytic oxidation(PEO)is effective surface treatment for necessary improvement of corrosion resistance of magnesium alloys.However,the∼1...Magnesium alloys are lightweight materials with great potential,and plasma electrolytic oxidation(PEO)is effective surface treatment for necessary improvement of corrosion resistance of magnesium alloys.However,the∼14µm thick and rough PEO protection layer has inferior wear resistance,which limits magnesium alloys as sliding or reciprocating parts,where magnesium alloys have special advantages by their inherent damping and denoising properties and attractive light-weighting.Here a novel super wear-resistant coating for magnesium alloys was achieved,via the discontinuous sealing(DCS)of a 1.3µm thick polytetrafluoroethylene(PTFE)polymer layer with an initial area fraction(A_(f))of 70%on the necessary PEO protection layer by selective spraying,and the wear resistance was exceptionally enhanced by∼5500 times in comparison with the base PEO coating.The initial surface roughness(Sa)under PEO+DCS(1.54µm)was imperfectly 59%higher than that under PEO and conventional continuous sealing(CS).Interestingly,DCS was surprisingly 20 times superior for enhancing wear resistance in contrast to CS.DCS induced nano-cracks that splitted DCS layer into multilayer nano-blocks,and DCS also provided extra space for the movement of nano-blocks,which resulted in rolling friction and nano lubrication.Further,DCS promoted mixed wear of the PTFE polymer layer and the PEO coating,and the PTFE layer(HV:6 Kg·mm^(−2),A_(f):92.2%)and the PEO coating(HV:310 Kg·mm^(−2),A_(f):7.8%)served as the soft matrix and the hard point,respectively.Moreover,the dynamic decrease of Sa by 29%during wear also contributed to the super wear resistance.The strategy of depositing a low-frictional discontinuous layer on a rough and hard layer or matrix also opens a window for achieving super wear-resistant coatings in other materials.展开更多
Aerosol deposition(AD)method is a kind of additive manufacturing technology for fabricating dense films such as metals and ceramics at room temperature.It resolves the challenge of integrating ceramic films onto tempe...Aerosol deposition(AD)method is a kind of additive manufacturing technology for fabricating dense films such as metals and ceramics at room temperature.It resolves the challenge of integrating ceramic films onto temperaturesensitive substrates,including metals,glasses,and polymers.It should be emphasized that the AD is a spray coating technology that uses powder without thermal assistance to generate films with high density.Compared to the traditional sputter-based approach,the AD shows several advantages in efficiency,convenience,better interfacial bonding and so on.Therefore,it opens some possibilities to the field of batteries,especially all-solidstate batteries(ASSBs)and draws much attention not only for research but also for large scale applications.The purpose of this work is to provide a critical review on the science and technology of AD as well as its applications in the field of batteries.The process,mechanism and effective parameters of AD,and recent developments in AD applications in the field of batteries will be systematically reviewed so that a trend for AD will be finally provided.展开更多
Ternary Ti-B-N coatings were synthesized on AISI 304 and Si wafer by plasma-enhanced chemical vapor deposition (PECVD) technique using a gaseous mixture of TiCl4,BCl3,H2,N2,and Ar.By virtue of X-ray diffraction analys...Ternary Ti-B-N coatings were synthesized on AISI 304 and Si wafer by plasma-enhanced chemical vapor deposition (PECVD) technique using a gaseous mixture of TiCl4,BCl3,H2,N2,and Ar.By virtue of X-ray diffraction analysis,X-ray photoelectron spectroscopy,scanning electron microscope,and high-resolution transmission electron microscope,the influences of B content on the microstructure and properties of Ti B N coatings were investigated systematically.The results indicated that the microstructure and mechanical properties of Ti-B-N coatings largely depend on the transformation from FCC-TiN phase to HCP-TiB2 phase.With increasing B content and decreasing N content in the coatings,the coating microstructure evolves gradually from FCC-TiN/a-BN to HCP-TiB2 /a-BN via FCC-TiN+HCP-TiB2/a-BN.The highest microhardness of about 34 GPa is achieved,which corresponds to the nanocomposite Ti-63%B-N (mole fraction) coating consisting of the HCP-TiB2 nano-crystallites and amorphous BN phase.The lowest friction-coefficient was observed for the nanocomposite Ti-41%B-N (mole fraction) coating consisting of the FCC-TiN nanocrystallites and amorphous BN展开更多
To prepare high wear resistance and high hardness coatings, electro-spark deposition was adopted for depositing an electrode of a mixture of 92wt%WC+8wt%Co on a cast steel roll substrate. The coating was characterize...To prepare high wear resistance and high hardness coatings, electro-spark deposition was adopted for depositing an electrode of a mixture of 92wt%WC+8wt%Co on a cast steel roll substrate. The coating was characterized by classical X-ray diffractometer (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX). The results indicate that the coating shows nanosized particulate structure and dendritic structure including columnar structure and equiaxed structure. The primary phases of the coating contain Fe3W3C, Co3W3C, Fe2C and Si2W. The coating has a low friction coefficient of 0.13, its average wear-resistance is 3.3 times that of the cast steel roll substrate and the main mechanism is abrasive wear. The maximum microhardness value of the coating is about 1573.9 Hv0.3. The study reveals that the electro-spark deposition process has the characteristic of better coating quality and the coating has higher wear resistance and hardness.展开更多
Porous α-Al2O3 thermal barrier coatings (TBCs) containing dispersed Pt particles were prepared by cathode plasma electrolytic deposition (CPED). The influence of the Pt particles on the microstructure of the coat...Porous α-Al2O3 thermal barrier coatings (TBCs) containing dispersed Pt particles were prepared by cathode plasma electrolytic deposition (CPED). The influence of the Pt particles on the microstructure of the coatings and the CPED process were studied. The prepared coatings were mainly composed of α-Al2O3. The average thickness of the coatings was approximately 100 μm. Such single-layer TBCs ex- hibited not only excellent high-temperature cyclic oxidation and spallation resistance, but also good thermal insulation properties. Porous α-Al2O3 TBCs inhibit further oxidation of alloy substrates because of their extremely low oxygen diffusion rate, provide good thermal insu- lation because of their porous structure, and exhibit excellent mechanical properties because of the toughening effect of the Pt particles and because of stress relaxation induced by deformation of the porous structure.展开更多
Zr/WC composite coating was prepared on the surface of Cr12MoV steel by electric spark deposition technology to change its surface properties. The surface and worn surface morphology of the coating were observed using...Zr/WC composite coating was prepared on the surface of Cr12MoV steel by electric spark deposition technology to change its surface properties. The surface and worn surface morphology of the coating were observed using scanning electron microscope. Dry friction and wear tests of the coatings were carried out at room temperature. The results show that the coating is continuous and uniform, and the thickness was about 50-60 μm. The microhardness of the coating surface was highest at 1140 HV_(200g), which was significantly higher than that of the substrate. The ear tests results show that the wear weight loss, wear volume and wear rate follow the following rules: Cr12MoV>WC coating> Zr/WC composite coating.展开更多
The hydroxyapatite(HA) ceramic coating was successfully prepared on Ti6A14V alloy by the hydrothermal-electrochemical deposition method with constant voltage model. The phases of deposits were analyzed by X-ray diff...The hydroxyapatite(HA) ceramic coating was successfully prepared on Ti6A14V alloy by the hydrothermal-electrochemical deposition method with constant voltage model. The phases of deposits were analyzed by X-ray diffraction. The releationship between crystallinity and depositing temperature was discussed. The microstructures of hydroxyapatite coating were observed by scanning electron microscope. The experimental results showed that the phases, crystaUinity and morphologies of deposits were influenced by depositing temperature (100℃, 120℃, 140℃, 160℃, 180℃ and 200℃, respectively). The special hydrothermal environment can lower the crystallization temperature of HA. The crystallinity of HA increases firstly and then decreases with the increase of temperature. There is little hydroxyapatite deposited on the Ti6A14V surface when the depositing temperature is 100℃. The HA deposition increases with the increase of the depositing temperature. And the HA morphologies are influenced by the depositing temperature.展开更多
Electro-spark deposition(ESD) was adopted for preparing high property coatings by depositing WC-8Co cemented carbide on an spheroidal graphite roll substrate.The microstructure and properties of the coating were inv...Electro-spark deposition(ESD) was adopted for preparing high property coatings by depositing WC-8Co cemented carbide on an spheroidal graphite roll substrate.The microstructure and properties of the coating were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM) with energy dispersive X-ray(EDX) and ball-disc configuration wear tester.The results show that nanosized particles and amorphous structures prevail in the coating which is metallurgically bonded to the substrate.The microstructures of the transition zone include columnar structure and equiaxed structure.The primary phases of the coating contain W2C, W6C2.54, Fe3W3C, and Co3W3C.The results of abrasive test show that the coating has low friction coefficients(μaverage = 0.18) and the wear mechanisms are mainly abrasive wear, fatigue wear, and oxidation wear.The maximum microhardness value of the coating is about 17410 N/mm2.The study reveals that the electro-spark deposition process has better coating quality and the coating has high wear resistance and hardness.展开更多
Magnesium coatings were fabricated on stainless steel substrates (1Cr11Ni2W2MoV) by a plane magnetron sputtering technique. The argon pressure and the substrate condition (including temperature and the substrate was r...Magnesium coatings were fabricated on stainless steel substrates (1Cr11Ni2W2MoV) by a plane magnetron sputtering technique. The argon pressure and the substrate condition (including temperature and the substrate was rotated or fixed) were varied in order to evaluate the influence of the parameters on the crystal orientation and morphology of the coating. The corrosion behavior of the coatings in 1 wt pct NaCI solution was studied by electrochemical methods. The results showed that all coatings exhibited preferred orientation (002) as the argon pressure increased from 0.2 to 0.4 Pa. The morphologies of the coatings varied with the argon pressure and with whether the substrate was rotated or fixed. The open circuit potential of the coatings was more positive than that of cast AZ91D magnesium alloy. However, the immersion test in 1 wt pct NaCI solution showed that the corrosion rates of the coatings were higher than that of cast AZ91D magnesium alloy.展开更多
The aim of this research is to pulse co-deposit nano-CeO2 particles into Ni-W-B alloy coatings in order to improve the surface properties. The influence of pulse frequency and duty circle on deposition rate, microhard...The aim of this research is to pulse co-deposit nano-CeO2 particles into Ni-W-B alloy coatings in order to improve the surface properties. The influence of pulse frequency and duty circle on deposition rate, microhardness and microstructures, and the influence of heat treatment temperature on phase structures, microhardness and abrasivity of Ni-W-B-CeO2 composite coatings were investigated. The results indicated that the pulse co-deposition of nickel, tungsten, boron and nano-CeO2 particle from the bath which nano-CeO2 particle was suspended by high speed mechanical stirring led to the Ni-W-B-CeO2 composite coatings, possessing better microhardness and abrasion resistance when heat-treated at 400 ℃ for 1 h. The microhardness as-deposited with 636 Hz and the deposition rate with 0.0281 mm·h-1 was the highest at pulse frequency with 1000 Hz and pulse duty circle with 10%. Microstructures analysis displays that decreasing pulse duty cycle leads to refinement in grain structures and the improvement of microstructures. X-ray diffraction shows that the composite coating as-deposited was mainly in the amorphous state and partially crystallized, but when heat treated at 400 ℃, the crystallization trend was strengthened further.展开更多
A codeposition of bioglass (BG) and hydroxyapatite (HA) on the substrate Ti6Al4V is realized in a nonaqueous solution system by inducing crystallization of HA on surface of the BG grain and electrophoresis deposition ...A codeposition of bioglass (BG) and hydroxyapatite (HA) on the substrate Ti6Al4V is realized in a nonaqueous solution system by inducing crystallization of HA on surface of the BG grain and electrophoresis deposition (EPD), and then a bioactive graded ceramic coating was obtained after sintering of the coating. This technique is a new method for making bioactive graded coating. The adhesive strength between the coating and the substrate reaches 18?MPa, and the better electrophoresis depositing parameters and optimal sintering procedure are obtained.展开更多
Electric-spark deposition (ESD) was adopted for depositing a Ti( CN) -based ceramic coating on the TC4 titanium alloy substrate using a laboratory-developed electric-spark deposition system, a nitrogen-sealed atmo...Electric-spark deposition (ESD) was adopted for depositing a Ti( CN) -based ceramic coating on the TC4 titanium alloy substrate using a laboratory-developed electric-spark deposition system, a nitrogen-sealed atmosphere and graphite electrode. The surface morphology, microstructure, interfacial behavior between the coatings and substrate, phase and element composition of the coatings were investigated by scanning electron microscope ( SEM ) , X-ray diffraction ( XRD ) , X-ray photoelectron spectroscopy ( XPS ) and Auger electron spectroscopy ( AES ) . Microhardness profile was measured with a Vickers microhardness tester. The results show that metallurgical bond between the coating and substrate is realized and the phase of coatings are made up of Ti( CN ) spherocrystal and dendritic crystal, TiV and C. Ti( CN) ceramic particles, which is in-situ synthesized by the reaction among titanium from the substrate, carbon from the graphite electrode and nitrogen from the shielding nitrogen gas, is about 600 mn and distributes dispersively among the coatings. Microharduess profile falls off with the coatings thickness increasing and the highest microhardness values of the superficial coating could be up to 1 496HV, which is six times more than that of the substrate.展开更多
Research is being conducted to study the effects of particulate deposition from contaminants in coal synthesis gas (syngas) on the mechanical properties of thermal barrier coatings (TBC) employed on integrated gasific...Research is being conducted to study the effects of particulate deposition from contaminants in coal synthesis gas (syngas) on the mechanical properties of thermal barrier coatings (TBC) employed on integrated gasification combined cycle (IGCC) turbine hot section airfoils. West Virginia University (WVU) had been working with US Department of Energy, National Energy Technology Laboratory (NETL) to simulate deposition on the pressure side of an IGCC turbine first stage vane. To model the deposition, coal fly ash was injected into the flow of a combustor facility and deposited onto TBC coated, angled film-cooled test articles in a high pressure (approximately 4 atm) and a high temperature (1560 K) environment. To investigate the interaction between the deposition and the TBC, a load-based multiple-partial unloading micro-indentation technique was used to quantitatively evaluate the mechanical properties of materials. The indentation results showed the Young’s Modulus of the ceramic top coat was higher in areas with deposition formation due to the penetration of the fly ash. This corresponds with the reduction of strain tolerance of the 7% yttria-stabilized zirconia (7YSZ) coatings.展开更多
Up-scaled deposition process of Teer-UDP850/4 has been established and used for massive production of CrTiAIN hard coatings in applications of anti-wear, cutting and forming tools. This deposition system uses four mag...Up-scaled deposition process of Teer-UDP850/4 has been established and used for massive production of CrTiAIN hard coatings in applications of anti-wear, cutting and forming tools. This deposition system uses four magnetrons that are arranged by unbalanced magnets to form closed magnetic field enabling the system running in high current density. Elemental metals of Cr, Ti and Al are used as the target materials which are co-deposited with nitrogen forming multialloy nitride, nanoscale multi-layer or superlattice hard coatings. The substrate turntable is desfgned as planet rotation mechanism with three folds so that components or tools with complicate geometry can be uniformly coated onto all their surfaces and cutting edges. The power units for the magnetrons are straight dc whilst the substrate is biased by pulsed dc. Two solid heaters are installed in the system to enable running a wide range of deposition temperature from 200°C to 500°C. The pumping system is powerful that incorporated with a polycold to pump the system to a good vacuum in a very short time. A front door and a movable substrate table are available to benefit easily loading and unloading. Deposition procedure, properties and performance of the coatings is also presented in this paper.展开更多
Electrospray,as a liquid source supply system,has been applied to chemical vapour deposition(CVD).In thermal CVD,the microstructure of the obtained films changes from dense to coarse granular because of the decreasi...Electrospray,as a liquid source supply system,has been applied to chemical vapour deposition(CVD).In thermal CVD,the microstructure of the obtained films changes from dense to coarse granular because of the decreasing surface temperature during deposition.Using the electrospray laser chemical vapour deposition method,we prepared homogenous alumina coatings.We found that laser irradiation was effective in compensating the surface temperature decrease,and an alpha-alumina coating with dense columnar microstructures was obtained at a deposition rate of 200 μm/h using 200 W Nd:YAG laser irradiation.展开更多
Mild steel is commonly used in the construction of Pipeline. The major problem of this Pipeline is corrosion. Effort is make my researchers to combat this problem. In this work Co-deposition of Ni-CoSiO_2 composite co...Mild steel is commonly used in the construction of Pipeline. The major problem of this Pipeline is corrosion. Effort is make my researchers to combat this problem. In this work Co-deposition of Ni-CoSiO_2 composite coating on mild steel was reported with the view to reduce this problem. The SiO_2 was varies from 5 to 25 wt% in the deposition. The microstructure, hardness values and potentiodynamic polarization in simulated sea water were determined. The results show that XRD pattern of the Ni Co deposited mild steel revealed the presence hard phases of NiO, Co_5Ni, Co_2Ni_3, Ni Co5 while that of Ni-CoSiO_2 deposited mild steel revealed the presence harder phases of NiOSiO_2, CoNi_7Si_2, Co_5Ni_2Si_3. The NiCo-25 SiO_2 deposited sample has smaller particle size than Ni-10 Co coating. Coating thickness of 110.7 mm was obtained for Ni-10 Co coating, while coating thickness of 135.7, 157.7, 165.0 mm were obtained at Ni-10 Co-x SiO_2(x=10, 15, 25 wt%). 99.90% corrosion resistance was achieved at Ni-Co-25 SiO_2. This improvement in corrosion resistance after composites coating could be attributed to the hard and fine structure obtained after coating.展开更多
Hydroxyapatite coatings were directly prepared on anodized titanium by electro-deposition method in a modified simulated body fluid.The configuration,structure and bioactivity of the coating were investigated with sca...Hydroxyapatite coatings were directly prepared on anodized titanium by electro-deposition method in a modified simulated body fluid.The configuration,structure and bioactivity of the coating were investigated with scanning electron microscopy(SEM),X-ray diffraction analyzer(XRD)and Fourier transform infrared spectros-copy(FTIR)techniques.The results demonstrated that pure and homogeneous hydroxyapatite coating can be obtained without any post-treatment.The prepared coating showed good bioactivity in simulated body fluid(SBF).The time required for a fully covered dense hydroxyapatite coatings was 4 days immersion in SBF.展开更多
Research is being conducted to study the degradation of thermal barrier coatings (TBC) employed on IGCC turbine hot section airfoils due to particulate deposition from contaminants in coal syn-thesis gas (syngas). Wes...Research is being conducted to study the degradation of thermal barrier coatings (TBC) employed on IGCC turbine hot section airfoils due to particulate deposition from contaminants in coal syn-thesis gas (syngas). West Virginia University (WVU) had been working with US Department of Energy, National Energy Technology Laboratory (NETL) to simulate deposition on the pressure side of an IGCC turbine first stage vane. To simulate the contaminant deposition, several TBC coated, angled film-cooled test articles were subjected to accelerated coal fly ash, which was injected into the flow of a combustor facility with a high pressure (approximately 4 atm) and a high temperature (1560 K) environment. To investigate the degradation of the TBCs due to particulate deposition, non-destructive tests were performed using scanning electron microscopy (SEM) evaluation and energy dispersive X-ray spectroscopy (EDS) examinations. The SEM evaluation was used to display the microstructure change within the layers of the TBC system directly related to the fly ash deposition. The SEM micrographs showed that deposition-TBC interaction made the YSZ coating more susceptible to delamination and promoted a dissolution-reprecipitation mechanism that changed the YSZ morphology and composition. The EDS examination provided elemental maps of the shallow infiltration depth of the fly ash and chemical composition spectrum results which showed yttria migration from the YSZ into the deposition.展开更多
By a novel technique-cathodic micro-arc electro-deposition (CMED), ZrO_2coatings were deposited on an FeCrAl alloy. Experimental results show that the necessary conditionsfor obtaining ZrO_2 coatings are to apply a pu...By a novel technique-cathodic micro-arc electro-deposition (CMED), ZrO_2coatings were deposited on an FeCrAl alloy. Experimental results show that the necessary conditionsfor obtaining ZrO_2 coatings are to apply a pulse peak voltage over a critical value and addmoderate amounts of ZrO_2 colloidal particles and Zr(NO_3)_4 in the aqueous solution. Theas-deposited coatings are porous because hydrogen, water, and other vapors are generated andreleased from the coatings to the solution during the spark reaction. The coatings containmonoclinic and tetragonal crystalline ZrO_2 with certain degree of amorphous structure. Theprocessing parameters and mechanism of CMED were discussed.展开更多
Ni-Al2O3 nano-composite coatings were fabricated by sediment co-deposition (SCD) from Watt’s type electrolyte containing nano-Al2O3 particles without any additives. For comparison, Ni-Al2O3 nano-composite coatings we...Ni-Al2O3 nano-composite coatings were fabricated by sediment co-deposition (SCD) from Watt’s type electrolyte containing nano-Al2O3 particles without any additives. For comparison, Ni-Al2O3 nano-composite coatings were prepared by conventional electro-plating (CEP) under experimental conditions. Effects of process parameters, such as nano-Al2O3 concentration in plating solution, current density, stirring rate, and bath temperature, on nano-Al2O3 content in composite coatings were investigated. The distribution of elements in deposit, and the bonding strength between coating and substrate was analyzed by electron probe microanalyzer (EPMA) and auto-scratch apparatus, respectively. It is found that the nano-Al2O3 concentration in plating solution, current density and stirring rate are three main factors affecting the particles content in deposit, and played a key role in the formation of composite coatings. The nano-Al2O3 content in composite coatings increased with increasing of nano-Al2O3 concentration in plating solution, current density and stirring rate to reach a maximum value, and then reduced slightly. The contents of nano-Al2O3 particles in composite coatings by the SCD technique were higher than that by the CEP technique. The co-deposited nano-Al2O3 particles embedded uniformly in the Ni matrix. The coating was well adhesion with substrate. It is demonstrated that the SCD technique is an efficient approach for improving the nano-Al2O3 content in Ni-Al2O3 composite coatings.展开更多
基金This work was financially supported by the Jiangsu Distinguished Professor Project,the Innovate UK(Project reference:10004694)the National Key R&D Program of China 2021YFB3401200.The Experimental Techniques Centre at Brunel University London and Nanjing University of Aeronautics and Astronautics are acknowledged.The authors also acknowledge the characterization facility at Shanghai Jiao Tong University,Central South University,University of Birmingham and University of Lille.
文摘Magnesium alloys are lightweight materials with great potential,and plasma electrolytic oxidation(PEO)is effective surface treatment for necessary improvement of corrosion resistance of magnesium alloys.However,the∼14µm thick and rough PEO protection layer has inferior wear resistance,which limits magnesium alloys as sliding or reciprocating parts,where magnesium alloys have special advantages by their inherent damping and denoising properties and attractive light-weighting.Here a novel super wear-resistant coating for magnesium alloys was achieved,via the discontinuous sealing(DCS)of a 1.3µm thick polytetrafluoroethylene(PTFE)polymer layer with an initial area fraction(A_(f))of 70%on the necessary PEO protection layer by selective spraying,and the wear resistance was exceptionally enhanced by∼5500 times in comparison with the base PEO coating.The initial surface roughness(Sa)under PEO+DCS(1.54µm)was imperfectly 59%higher than that under PEO and conventional continuous sealing(CS).Interestingly,DCS was surprisingly 20 times superior for enhancing wear resistance in contrast to CS.DCS induced nano-cracks that splitted DCS layer into multilayer nano-blocks,and DCS also provided extra space for the movement of nano-blocks,which resulted in rolling friction and nano lubrication.Further,DCS promoted mixed wear of the PTFE polymer layer and the PEO coating,and the PTFE layer(HV:6 Kg·mm^(−2),A_(f):92.2%)and the PEO coating(HV:310 Kg·mm^(−2),A_(f):7.8%)served as the soft matrix and the hard point,respectively.Moreover,the dynamic decrease of Sa by 29%during wear also contributed to the super wear resistance.The strategy of depositing a low-frictional discontinuous layer on a rough and hard layer or matrix also opens a window for achieving super wear-resistant coatings in other materials.
基金supported by National University of Singapore (Chongqing) Research InstituteNational University of Singapore+2 种基金Chongqing Postdoctoral Research Special FundingOverseas Postdoctoral Research Start-up FundingNatural Science Foundation of Chongqing, China (cstc2021jcyj-msxmX0086)
文摘Aerosol deposition(AD)method is a kind of additive manufacturing technology for fabricating dense films such as metals and ceramics at room temperature.It resolves the challenge of integrating ceramic films onto temperaturesensitive substrates,including metals,glasses,and polymers.It should be emphasized that the AD is a spray coating technology that uses powder without thermal assistance to generate films with high density.Compared to the traditional sputter-based approach,the AD shows several advantages in efficiency,convenience,better interfacial bonding and so on.Therefore,it opens some possibilities to the field of batteries,especially all-solidstate batteries(ASSBs)and draws much attention not only for research but also for large scale applications.The purpose of this work is to provide a critical review on the science and technology of AD as well as its applications in the field of batteries.The process,mechanism and effective parameters of AD,and recent developments in AD applications in the field of batteries will be systematically reviewed so that a trend for AD will be finally provided.
基金funded by a grant from the National Core Research Center(NCRC)Program through the National Research Foundation of Korea funded by the Ministry of Education,Science and Technology(No.2012-0000-957)by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy,Republic of Korea
文摘Ternary Ti-B-N coatings were synthesized on AISI 304 and Si wafer by plasma-enhanced chemical vapor deposition (PECVD) technique using a gaseous mixture of TiCl4,BCl3,H2,N2,and Ar.By virtue of X-ray diffraction analysis,X-ray photoelectron spectroscopy,scanning electron microscope,and high-resolution transmission electron microscope,the influences of B content on the microstructure and properties of Ti B N coatings were investigated systematically.The results indicated that the microstructure and mechanical properties of Ti-B-N coatings largely depend on the transformation from FCC-TiN phase to HCP-TiB2 phase.With increasing B content and decreasing N content in the coatings,the coating microstructure evolves gradually from FCC-TiN/a-BN to HCP-TiB2 /a-BN via FCC-TiN+HCP-TiB2/a-BN.The highest microhardness of about 34 GPa is achieved,which corresponds to the nanocomposite Ti-63%B-N (mole fraction) coating consisting of the HCP-TiB2 nano-crystallites and amorphous BN phase.The lowest friction-coefficient was observed for the nanocomposite Ti-41%B-N (mole fraction) coating consisting of the FCC-TiN nanocrystallites and amorphous BN
基金supported by the International Science and Technology Cooperation Project of the Ministry of Science and Technology of China (No.2006DFA52240)
文摘To prepare high wear resistance and high hardness coatings, electro-spark deposition was adopted for depositing an electrode of a mixture of 92wt%WC+8wt%Co on a cast steel roll substrate. The coating was characterized by classical X-ray diffractometer (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX). The results indicate that the coating shows nanosized particulate structure and dendritic structure including columnar structure and equiaxed structure. The primary phases of the coating contain Fe3W3C, Co3W3C, Fe2C and Si2W. The coating has a low friction coefficient of 0.13, its average wear-resistance is 3.3 times that of the cast steel roll substrate and the main mechanism is abrasive wear. The maximum microhardness value of the coating is about 1573.9 Hv0.3. The study reveals that the electro-spark deposition process has the characteristic of better coating quality and the coating has higher wear resistance and hardness.
基金supported by the Chinese National Natural Science Foundation (Grant No. 51271030)
文摘Porous α-Al2O3 thermal barrier coatings (TBCs) containing dispersed Pt particles were prepared by cathode plasma electrolytic deposition (CPED). The influence of the Pt particles on the microstructure of the coatings and the CPED process were studied. The prepared coatings were mainly composed of α-Al2O3. The average thickness of the coatings was approximately 100 μm. Such single-layer TBCs ex- hibited not only excellent high-temperature cyclic oxidation and spallation resistance, but also good thermal insulation properties. Porous α-Al2O3 TBCs inhibit further oxidation of alloy substrates because of their extremely low oxygen diffusion rate, provide good thermal insu- lation because of their porous structure, and exhibit excellent mechanical properties because of the toughening effect of the Pt particles and because of stress relaxation induced by deformation of the porous structure.
基金supported by Key Projects of Strategic International Scientific and Technological Innovation Cooperation(Grant No.2016YFE0201300)
文摘Zr/WC composite coating was prepared on the surface of Cr12MoV steel by electric spark deposition technology to change its surface properties. The surface and worn surface morphology of the coating were observed using scanning electron microscope. Dry friction and wear tests of the coatings were carried out at room temperature. The results show that the coating is continuous and uniform, and the thickness was about 50-60 μm. The microhardness of the coating surface was highest at 1140 HV_(200g), which was significantly higher than that of the substrate. The ear tests results show that the wear weight loss, wear volume and wear rate follow the following rules: Cr12MoV>WC coating> Zr/WC composite coating.
基金Funded in Part by the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology)(2013-KF7)the Research Fund of Science and Technology Commission of Shanghai Municipality(Nos.09ZR1422100,11441900500,11441900501)
文摘The hydroxyapatite(HA) ceramic coating was successfully prepared on Ti6A14V alloy by the hydrothermal-electrochemical deposition method with constant voltage model. The phases of deposits were analyzed by X-ray diffraction. The releationship between crystallinity and depositing temperature was discussed. The microstructures of hydroxyapatite coating were observed by scanning electron microscope. The experimental results showed that the phases, crystaUinity and morphologies of deposits were influenced by depositing temperature (100℃, 120℃, 140℃, 160℃, 180℃ and 200℃, respectively). The special hydrothermal environment can lower the crystallization temperature of HA. The crystallinity of HA increases firstly and then decreases with the increase of temperature. There is little hydroxyapatite deposited on the Ti6A14V surface when the depositing temperature is 100℃. The HA deposition increases with the increase of the depositing temperature. And the HA morphologies are influenced by the depositing temperature.
基金supported by the International Science and Technology Cooperation Project of the Ministry of Science and Technology of China (No. 2006DFA52240)
文摘Electro-spark deposition(ESD) was adopted for preparing high property coatings by depositing WC-8Co cemented carbide on an spheroidal graphite roll substrate.The microstructure and properties of the coating were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM) with energy dispersive X-ray(EDX) and ball-disc configuration wear tester.The results show that nanosized particles and amorphous structures prevail in the coating which is metallurgically bonded to the substrate.The microstructures of the transition zone include columnar structure and equiaxed structure.The primary phases of the coating contain W2C, W6C2.54, Fe3W3C, and Co3W3C.The results of abrasive test show that the coating has low friction coefficients(μaverage = 0.18) and the wear mechanisms are mainly abrasive wear, fatigue wear, and oxidation wear.The maximum microhardness value of the coating is about 17410 N/mm2.The study reveals that the electro-spark deposition process has better coating quality and the coating has high wear resistance and hardness.
文摘Magnesium coatings were fabricated on stainless steel substrates (1Cr11Ni2W2MoV) by a plane magnetron sputtering technique. The argon pressure and the substrate condition (including temperature and the substrate was rotated or fixed) were varied in order to evaluate the influence of the parameters on the crystal orientation and morphology of the coating. The corrosion behavior of the coatings in 1 wt pct NaCI solution was studied by electrochemical methods. The results showed that all coatings exhibited preferred orientation (002) as the argon pressure increased from 0.2 to 0.4 Pa. The morphologies of the coatings varied with the argon pressure and with whether the substrate was rotated or fixed. The open circuit potential of the coatings was more positive than that of cast AZ91D magnesium alloy. However, the immersion test in 1 wt pct NaCI solution showed that the corrosion rates of the coatings were higher than that of cast AZ91D magnesium alloy.
基金Projects supported by Applied Basic Research Plans Programof Yunnan Province (2007E 187M)Scientific Research Fund(2006-02)Analysis and Measurement Research Fund (2007-22) of Kunming University of Science and Technology
文摘The aim of this research is to pulse co-deposit nano-CeO2 particles into Ni-W-B alloy coatings in order to improve the surface properties. The influence of pulse frequency and duty circle on deposition rate, microhardness and microstructures, and the influence of heat treatment temperature on phase structures, microhardness and abrasivity of Ni-W-B-CeO2 composite coatings were investigated. The results indicated that the pulse co-deposition of nickel, tungsten, boron and nano-CeO2 particle from the bath which nano-CeO2 particle was suspended by high speed mechanical stirring led to the Ni-W-B-CeO2 composite coatings, possessing better microhardness and abrasion resistance when heat-treated at 400 ℃ for 1 h. The microhardness as-deposited with 636 Hz and the deposition rate with 0.0281 mm·h-1 was the highest at pulse frequency with 1000 Hz and pulse duty circle with 10%. Microstructures analysis displays that decreasing pulse duty cycle leads to refinement in grain structures and the improvement of microstructures. X-ray diffraction shows that the composite coating as-deposited was mainly in the amorphous state and partially crystallized, but when heat treated at 400 ℃, the crystallization trend was strengthened further.
文摘A codeposition of bioglass (BG) and hydroxyapatite (HA) on the substrate Ti6Al4V is realized in a nonaqueous solution system by inducing crystallization of HA on surface of the BG grain and electrophoresis deposition (EPD), and then a bioactive graded ceramic coating was obtained after sintering of the coating. This technique is a new method for making bioactive graded coating. The adhesive strength between the coating and the substrate reaches 18?MPa, and the better electrophoresis depositing parameters and optimal sintering procedure are obtained.
基金The work was supported by the Natural Science Foundation of Hebei Province of China under Grant No. E2007000566.
文摘Electric-spark deposition (ESD) was adopted for depositing a Ti( CN) -based ceramic coating on the TC4 titanium alloy substrate using a laboratory-developed electric-spark deposition system, a nitrogen-sealed atmosphere and graphite electrode. The surface morphology, microstructure, interfacial behavior between the coatings and substrate, phase and element composition of the coatings were investigated by scanning electron microscope ( SEM ) , X-ray diffraction ( XRD ) , X-ray photoelectron spectroscopy ( XPS ) and Auger electron spectroscopy ( AES ) . Microhardness profile was measured with a Vickers microhardness tester. The results show that metallurgical bond between the coating and substrate is realized and the phase of coatings are made up of Ti( CN ) spherocrystal and dendritic crystal, TiV and C. Ti( CN) ceramic particles, which is in-situ synthesized by the reaction among titanium from the substrate, carbon from the graphite electrode and nitrogen from the shielding nitrogen gas, is about 600 mn and distributes dispersively among the coatings. Microharduess profile falls off with the coatings thickness increasing and the highest microhardness values of the superficial coating could be up to 1 496HV, which is six times more than that of the substrate.
文摘Research is being conducted to study the effects of particulate deposition from contaminants in coal synthesis gas (syngas) on the mechanical properties of thermal barrier coatings (TBC) employed on integrated gasification combined cycle (IGCC) turbine hot section airfoils. West Virginia University (WVU) had been working with US Department of Energy, National Energy Technology Laboratory (NETL) to simulate deposition on the pressure side of an IGCC turbine first stage vane. To model the deposition, coal fly ash was injected into the flow of a combustor facility and deposited onto TBC coated, angled film-cooled test articles in a high pressure (approximately 4 atm) and a high temperature (1560 K) environment. To investigate the interaction between the deposition and the TBC, a load-based multiple-partial unloading micro-indentation technique was used to quantitatively evaluate the mechanical properties of materials. The indentation results showed the Young’s Modulus of the ceramic top coat was higher in areas with deposition formation due to the penetration of the fly ash. This corresponds with the reduction of strain tolerance of the 7% yttria-stabilized zirconia (7YSZ) coatings.
文摘Up-scaled deposition process of Teer-UDP850/4 has been established and used for massive production of CrTiAIN hard coatings in applications of anti-wear, cutting and forming tools. This deposition system uses four magnetrons that are arranged by unbalanced magnets to form closed magnetic field enabling the system running in high current density. Elemental metals of Cr, Ti and Al are used as the target materials which are co-deposited with nitrogen forming multialloy nitride, nanoscale multi-layer or superlattice hard coatings. The substrate turntable is desfgned as planet rotation mechanism with three folds so that components or tools with complicate geometry can be uniformly coated onto all their surfaces and cutting edges. The power units for the magnetrons are straight dc whilst the substrate is biased by pulsed dc. Two solid heaters are installed in the system to enable running a wide range of deposition temperature from 200°C to 500°C. The pumping system is powerful that incorporated with a polycold to pump the system to a good vacuum in a very short time. A front door and a movable substrate table are available to benefit easily loading and unloading. Deposition procedure, properties and performance of the coatings is also presented in this paper.
文摘Electrospray,as a liquid source supply system,has been applied to chemical vapour deposition(CVD).In thermal CVD,the microstructure of the obtained films changes from dense to coarse granular because of the decreasing surface temperature during deposition.Using the electrospray laser chemical vapour deposition method,we prepared homogenous alumina coatings.We found that laser irradiation was effective in compensating the surface temperature decrease,and an alpha-alumina coating with dense columnar microstructures was obtained at a deposition rate of 200 μm/h using 200 W Nd:YAG laser irradiation.
文摘Mild steel is commonly used in the construction of Pipeline. The major problem of this Pipeline is corrosion. Effort is make my researchers to combat this problem. In this work Co-deposition of Ni-CoSiO_2 composite coating on mild steel was reported with the view to reduce this problem. The SiO_2 was varies from 5 to 25 wt% in the deposition. The microstructure, hardness values and potentiodynamic polarization in simulated sea water were determined. The results show that XRD pattern of the Ni Co deposited mild steel revealed the presence hard phases of NiO, Co_5Ni, Co_2Ni_3, Ni Co5 while that of Ni-CoSiO_2 deposited mild steel revealed the presence harder phases of NiOSiO_2, CoNi_7Si_2, Co_5Ni_2Si_3. The NiCo-25 SiO_2 deposited sample has smaller particle size than Ni-10 Co coating. Coating thickness of 110.7 mm was obtained for Ni-10 Co coating, while coating thickness of 135.7, 157.7, 165.0 mm were obtained at Ni-10 Co-x SiO_2(x=10, 15, 25 wt%). 99.90% corrosion resistance was achieved at Ni-Co-25 SiO_2. This improvement in corrosion resistance after composites coating could be attributed to the hard and fine structure obtained after coating.
基金Supported by the Young Scholars Fund of Beijing University of Chemical Technology(QN0713)
文摘Hydroxyapatite coatings were directly prepared on anodized titanium by electro-deposition method in a modified simulated body fluid.The configuration,structure and bioactivity of the coating were investigated with scanning electron microscopy(SEM),X-ray diffraction analyzer(XRD)and Fourier transform infrared spectros-copy(FTIR)techniques.The results demonstrated that pure and homogeneous hydroxyapatite coating can be obtained without any post-treatment.The prepared coating showed good bioactivity in simulated body fluid(SBF).The time required for a fully covered dense hydroxyapatite coatings was 4 days immersion in SBF.
文摘Research is being conducted to study the degradation of thermal barrier coatings (TBC) employed on IGCC turbine hot section airfoils due to particulate deposition from contaminants in coal syn-thesis gas (syngas). West Virginia University (WVU) had been working with US Department of Energy, National Energy Technology Laboratory (NETL) to simulate deposition on the pressure side of an IGCC turbine first stage vane. To simulate the contaminant deposition, several TBC coated, angled film-cooled test articles were subjected to accelerated coal fly ash, which was injected into the flow of a combustor facility with a high pressure (approximately 4 atm) and a high temperature (1560 K) environment. To investigate the degradation of the TBCs due to particulate deposition, non-destructive tests were performed using scanning electron microscopy (SEM) evaluation and energy dispersive X-ray spectroscopy (EDS) examinations. The SEM evaluation was used to display the microstructure change within the layers of the TBC system directly related to the fly ash deposition. The SEM micrographs showed that deposition-TBC interaction made the YSZ coating more susceptible to delamination and promoted a dissolution-reprecipitation mechanism that changed the YSZ morphology and composition. The EDS examination provided elemental maps of the shallow infiltration depth of the fly ash and chemical composition spectrum results which showed yttria migration from the YSZ into the deposition.
基金This work was financially supported by the National Natural Science Foundation of China (No.59971009) Beijing Key Laboratory for Corrosion, Erosion and Surface Technology.
文摘By a novel technique-cathodic micro-arc electro-deposition (CMED), ZrO_2coatings were deposited on an FeCrAl alloy. Experimental results show that the necessary conditionsfor obtaining ZrO_2 coatings are to apply a pulse peak voltage over a critical value and addmoderate amounts of ZrO_2 colloidal particles and Zr(NO_3)_4 in the aqueous solution. Theas-deposited coatings are porous because hydrogen, water, and other vapors are generated andreleased from the coatings to the solution during the spark reaction. The coatings containmonoclinic and tetragonal crystalline ZrO_2 with certain degree of amorphous structure. Theprocessing parameters and mechanism of CMED were discussed.
基金Supported by the National Natural Science Foundation of China (Grant No 50234020 and 50474055) and the of Northeastern University
文摘Ni-Al2O3 nano-composite coatings were fabricated by sediment co-deposition (SCD) from Watt’s type electrolyte containing nano-Al2O3 particles without any additives. For comparison, Ni-Al2O3 nano-composite coatings were prepared by conventional electro-plating (CEP) under experimental conditions. Effects of process parameters, such as nano-Al2O3 concentration in plating solution, current density, stirring rate, and bath temperature, on nano-Al2O3 content in composite coatings were investigated. The distribution of elements in deposit, and the bonding strength between coating and substrate was analyzed by electron probe microanalyzer (EPMA) and auto-scratch apparatus, respectively. It is found that the nano-Al2O3 concentration in plating solution, current density and stirring rate are three main factors affecting the particles content in deposit, and played a key role in the formation of composite coatings. The nano-Al2O3 content in composite coatings increased with increasing of nano-Al2O3 concentration in plating solution, current density and stirring rate to reach a maximum value, and then reduced slightly. The contents of nano-Al2O3 particles in composite coatings by the SCD technique were higher than that by the CEP technique. The co-deposited nano-Al2O3 particles embedded uniformly in the Ni matrix. The coating was well adhesion with substrate. It is demonstrated that the SCD technique is an efficient approach for improving the nano-Al2O3 content in Ni-Al2O3 composite coatings.