1 Results There is an increasing demand for producing high performance ceramic films at a reduced cost. This paper describes an innovative and cost-effective method of producing nanostructured ceramic films based on E...1 Results There is an increasing demand for producing high performance ceramic films at a reduced cost. This paper describes an innovative and cost-effective method of producing nanostructured ceramic films based on Electrostatic Spray Assisted Vapour Deposition (ESAVD). ESAVD is a variant of chemical vapour deposition process which involves spraying atomised charged precursor droplets across an electric field where the precursor undergo decomposition and heterogeneous chemical reaction near the heat...展开更多
Surface-modified BaTiO_(3)of 230 nm average grain size were synthesized by coating BaTiO_(3)particles with 3 wt.%Al2O_(3)and 1 wt.%SiO2.Ceramic films of different thicknesses were prepared via tape casting and laminat...Surface-modified BaTiO_(3)of 230 nm average grain size were synthesized by coating BaTiO_(3)particles with 3 wt.%Al2O_(3)and 1 wt.%SiO2.Ceramic films of different thicknesses were prepared via tape casting and laminating processes followed by two-steps sintering method.After sintering,the average grain size of Surface-modified BaTiO_(3)ceramic slightly increased to 275 nm,and great enhancement of AC breakdown strength(BDS)from 184 kV/cm to 665 kV/cm was obtained as the thickness of ceramic films decreased from 63μm to 12μm,resulting in improvement of discharge energy density from 1.14 J/cm3to 4.06 J/cm3.Because of their low-cost,easily fabrication,lead-free,improved AC BDS and discharge energy density,surface-modified BaTiO_(3)ceramic films appeared promising for applications in multilayer energy storage capacitors.展开更多
Room-temperature fabrication of functional ceramic films using powder aerosol deposition(AD)is important for practical applications.However,the as-processed ferroelectric films show unusual temperature-dependent diele...Room-temperature fabrication of functional ceramic films using powder aerosol deposition(AD)is important for practical applications.However,the as-processed ferroelectric films show unusual temperature-dependent dielectric response,including enhanced conductivity in the as-processed state and subsequent significant increase in the permittivity following heat treatment.In this work,we investigate the influence of the residual internal stresses developed during the high-impact consolidation process on the dielectric response.Moreover,the recombination of charged defects generated during deposition is driven by the temperature and the atmospheric condition during the heat treatment as well as the carrier gas type used during deposition.Thermal treatment up to 500℃ in different atmospheres was used to tune the dielectric and ferroelectric response,highlighting that irrespective of the type of carrier gas,AD deposition process induces charged defects in polar oxide ceramics that can be reduced through heat-treatment far-below their bulk sintering temperature.Macroscopic electromechanical properties are contrasted to in-situ heating scanning transmission electron microscopy to observe possible local effects,such as crystallization,grain growth,crystal defect structure,or grain reorientation.In addition X-ray diffraction and X-ray photoelectron spectroscopy studies were conducted to gain insight into the effect of annealing on the crystal structure and local moisture adsorption.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
To reduce time and energy during thermal binder removal in the ceramic process, plasma surface treatment was applied before the lamination process.The adhesion strength in the lamination films was enhanced by oxidativ...To reduce time and energy during thermal binder removal in the ceramic process, plasma surface treatment was applied before the lamination process.The adhesion strength in the lamination films was enhanced by oxidative plasma treatment of the porous green ceramic film with polymeric binding materials.The oxygen plasma characteristics were investigated through experimental parameters and weight loss analysis.The experimental results revealed the need for parameter analysis,including gas material,process time,flow rate,and discharge power,and supported a mechanism consisting of competing ablation and deposition processes.The weight loss analysis was conducted for cyclic plasma treatment rather than continuous plasma treatment for the purpose of improving the film’s permeability by suppressing deposition of the ablated species.The cyclic plasma treatment improved the permeability compared to the continuous plasma treatment.展开更多
In an appropriate electrochemical environment, the discrete thermal electron emission could be induced in the micro area due to the uneven distribution of electron flux on the anode surface. Thus an oxygen molecule co...In an appropriate electrochemical environment, the discrete thermal electron emission could be induced in the micro area due to the uneven distribution of electron flux on the anode surface. Thus an oxygen molecule could be ionized at the liquid-solid interface after collision, and then oxygen plasma with distribution characteristics would be formed. The plasma electrolytic oxidation(PEO) could happen at the liquid-solid interface. In this work, the low carbon steel was used to study the deburring process by PEO at a high frequency(70000 Hz)pulse DC mode. Its burr height H from 3.23 mm to 0.04 mm was removed to form a smooth surface within 6 min. The values of corrosion potential and current density for the untreated sample were -0.667 V and 6.735×10^(-5)A/cm^2, respectively. But for the treated sample, the corrosion potential and current density were relatively lower,-0.354 V and 1.19×10^(-7)A/cm^2.Therefore, PEO was expected to be a new deburring method of carbon steel for the material processing field.展开更多
Plasma electrolytic oxidation(PEO) films on AZ31 magnesium alloys were prepared in alkaline silicate electrolytes(base electrolyte) with the addition of different volume concentrations of CH3 OH,which was used to ...Plasma electrolytic oxidation(PEO) films on AZ31 magnesium alloys were prepared in alkaline silicate electrolytes(base electrolyte) with the addition of different volume concentrations of CH3 OH,which was used to adjust the thickness of the vapor sheath.The compositions,morphologies,and thicknesses of ceramic layers formed with different CH3OH concentrations were determined via X-ray diffraction(XRD),energy-dispersive spectroscopy(EDS),and scanning electron microscopy(SEM).Corrosion behavior of the oxide films was evaluated in 3.5wt.% NaCl solution using potentiodynamic polarization tests.PEO coatings mainly comprised Mg,MgO,and Mg2SiO4.The addition of CH_3OH in base electrolytes affected the thickness,pores diameter,and Mg2SiO4 content in the films.The films formed in the electrolyte containing 12% CH3OH exhibited the highest thickness.The coatings formed in the electrolyte containing different concentrations of CH3OH exhibited similar corrosion resistance.The energy consumption of PEO markedly decreased upon the addition of CH3OH to the electrolytes.The result is helpful for energy saving in the PEO process.e展开更多
K_(0.5)Na_(0.5)NbO_(3)-SrTiO_(3)(KNN-STO)thin films of different compositions were prepared by the chemical solution deposition method.While structural investigations confirmed the formation of perovskite solid soluti...K_(0.5)Na_(0.5)NbO_(3)-SrTiO_(3)(KNN-STO)thin films of different compositions were prepared by the chemical solution deposition method.While structural investigations confirmed the formation of perovskite solid solution in all developed films,dieletric experiments revealed a relaxor broad dispersive maximum in the sample with 15 mol%of STO,exhibiting for a thin film high ε′~330 at~210K.The history-dependent effects of this relaxor sample were compared to those of KNN STO ceramics and,furthermore,shown to be much weaker than in widely used lead-based ferroelectric and relaxor(Pb,L a)(Zr,Ti)O_(3) ceramics:While fatigue endurance results revealed a slight drop in polarization after 3 × 10^(5) switching cycles,the results of aging of the dielectric constant revealed no notable decrease in its values after 10^(6)s.展开更多
文摘1 Results There is an increasing demand for producing high performance ceramic films at a reduced cost. This paper describes an innovative and cost-effective method of producing nanostructured ceramic films based on Electrostatic Spray Assisted Vapour Deposition (ESAVD). ESAVD is a variant of chemical vapour deposition process which involves spraying atomised charged precursor droplets across an electric field where the precursor undergo decomposition and heterogeneous chemical reaction near the heat...
基金The work was supported by Ministry of Sciences and Tech-nology of China through National Basic Research Program of China(973 Program 2015CB654604)National Natural Science Foundation of China for Creative Research Groups(Grant No.51221291)+1 种基金National Natural Science Foundation of China(Grant No.51272123)CBMI Construction Co.,Ltd.
文摘Surface-modified BaTiO_(3)of 230 nm average grain size were synthesized by coating BaTiO_(3)particles with 3 wt.%Al2O_(3)and 1 wt.%SiO2.Ceramic films of different thicknesses were prepared via tape casting and laminating processes followed by two-steps sintering method.After sintering,the average grain size of Surface-modified BaTiO_(3)ceramic slightly increased to 275 nm,and great enhancement of AC breakdown strength(BDS)from 184 kV/cm to 665 kV/cm was obtained as the thickness of ceramic films decreased from 63μm to 12μm,resulting in improvement of discharge energy density from 1.14 J/cm3to 4.06 J/cm3.Because of their low-cost,easily fabrication,lead-free,improved AC BDS and discharge energy density,surface-modified BaTiO_(3)ceramic films appeared promising for applications in multilayer energy storage capacitors.
基金financial support for this work from the Deutsche Forschungsgemeinschaft(DFG)under WE4972/2 and GRK2495Ffunding from the Slovenian Research Agency within programmes P2-0105 and P2-0393 and projects J2-2497,J2-3041,and bilateral project BIeDE/20-21-012.
文摘Room-temperature fabrication of functional ceramic films using powder aerosol deposition(AD)is important for practical applications.However,the as-processed ferroelectric films show unusual temperature-dependent dielectric response,including enhanced conductivity in the as-processed state and subsequent significant increase in the permittivity following heat treatment.In this work,we investigate the influence of the residual internal stresses developed during the high-impact consolidation process on the dielectric response.Moreover,the recombination of charged defects generated during deposition is driven by the temperature and the atmospheric condition during the heat treatment as well as the carrier gas type used during deposition.Thermal treatment up to 500℃ in different atmospheres was used to tune the dielectric and ferroelectric response,highlighting that irrespective of the type of carrier gas,AD deposition process induces charged defects in polar oxide ceramics that can be reduced through heat-treatment far-below their bulk sintering temperature.Macroscopic electromechanical properties are contrasted to in-situ heating scanning transmission electron microscopy to observe possible local effects,such as crystallization,grain growth,crystal defect structure,or grain reorientation.In addition X-ray diffraction and X-ray photoelectron spectroscopy studies were conducted to gain insight into the effect of annealing on the crystal structure and local moisture adsorption.
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supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education, Science and Technology(2011-0013211).
文摘To reduce time and energy during thermal binder removal in the ceramic process, plasma surface treatment was applied before the lamination process.The adhesion strength in the lamination films was enhanced by oxidative plasma treatment of the porous green ceramic film with polymeric binding materials.The oxygen plasma characteristics were investigated through experimental parameters and weight loss analysis.The experimental results revealed the need for parameter analysis,including gas material,process time,flow rate,and discharge power,and supported a mechanism consisting of competing ablation and deposition processes.The weight loss analysis was conducted for cyclic plasma treatment rather than continuous plasma treatment for the purpose of improving the film’s permeability by suppressing deposition of the ablated species.The cyclic plasma treatment improved the permeability compared to the continuous plasma treatment.
基金supported by National Natural Science Foundation of China(No.51571114)Natural Science Foundation of Jiangsu Province,China(No.BK20130935)
文摘In an appropriate electrochemical environment, the discrete thermal electron emission could be induced in the micro area due to the uneven distribution of electron flux on the anode surface. Thus an oxygen molecule could be ionized at the liquid-solid interface after collision, and then oxygen plasma with distribution characteristics would be formed. The plasma electrolytic oxidation(PEO) could happen at the liquid-solid interface. In this work, the low carbon steel was used to study the deburring process by PEO at a high frequency(70000 Hz)pulse DC mode. Its burr height H from 3.23 mm to 0.04 mm was removed to form a smooth surface within 6 min. The values of corrosion potential and current density for the untreated sample were -0.667 V and 6.735×10^(-5)A/cm^2, respectively. But for the treated sample, the corrosion potential and current density were relatively lower,-0.354 V and 1.19×10^(-7)A/cm^2.Therefore, PEO was expected to be a new deburring method of carbon steel for the material processing field.
基金supported by National Natural Science Foundation of China(No.21376088)the Project of Production,Education and Research,Guangdong Province and Ministry of Education(Nos.2012B09100063,2012A090300015)Guangzhou Science and Technology Plan Projects of China(No.2014Y2-00042)
文摘Plasma electrolytic oxidation(PEO) films on AZ31 magnesium alloys were prepared in alkaline silicate electrolytes(base electrolyte) with the addition of different volume concentrations of CH3 OH,which was used to adjust the thickness of the vapor sheath.The compositions,morphologies,and thicknesses of ceramic layers formed with different CH3OH concentrations were determined via X-ray diffraction(XRD),energy-dispersive spectroscopy(EDS),and scanning electron microscopy(SEM).Corrosion behavior of the oxide films was evaluated in 3.5wt.% NaCl solution using potentiodynamic polarization tests.PEO coatings mainly comprised Mg,MgO,and Mg2SiO4.The addition of CH_3OH in base electrolytes affected the thickness,pores diameter,and Mg2SiO4 content in the films.The films formed in the electrolyte containing 12% CH3OH exhibited the highest thickness.The coatings formed in the electrolyte containing different concentrations of CH3OH exhibited similar corrosion resistance.The energy consumption of PEO markedly decreased upon the addition of CH3OH to the electrolytes.The result is helpful for energy saving in the PEO process.e
基金This project was financially supported by Slovenian Research Agency under programs P1-0125 and P2-0105 and projects PR-02908,J2-1227,and PR-03099by Ministry of Education,Science and Sport of Republic of Slovenia under Project PR-05648.
文摘K_(0.5)Na_(0.5)NbO_(3)-SrTiO_(3)(KNN-STO)thin films of different compositions were prepared by the chemical solution deposition method.While structural investigations confirmed the formation of perovskite solid solution in all developed films,dieletric experiments revealed a relaxor broad dispersive maximum in the sample with 15 mol%of STO,exhibiting for a thin film high ε′~330 at~210K.The history-dependent effects of this relaxor sample were compared to those of KNN STO ceramics and,furthermore,shown to be much weaker than in widely used lead-based ferroelectric and relaxor(Pb,L a)(Zr,Ti)O_(3) ceramics:While fatigue endurance results revealed a slight drop in polarization after 3 × 10^(5) switching cycles,the results of aging of the dielectric constant revealed no notable decrease in its values after 10^(6)s.