The Pr and Ta separately doped FTO(10 at.% F incorporated Sn O2) films are fabricated via spray pyrolysis. The microstructural, topographic, optical, and electrical features of fluorine-doped TO(FTO) films are inv...The Pr and Ta separately doped FTO(10 at.% F incorporated Sn O2) films are fabricated via spray pyrolysis. The microstructural, topographic, optical, and electrical features of fluorine-doped TO(FTO) films are investigated as functions of Pr and Ta dopant concentrations. The x-ray diffraction(XRD) measurements reveal that all deposited films show polycrystalline tin oxide crystal property. FTO film has(200) preferential orientation, but this orientation changes to(211) direction with Pr and Ta doping ratio increasing. Atomic force microscopy(AFM) and scanning electron microscopy(SEM) analyses show that all films have uniform and homogenous nanoparticle distributions. Furthermore, morphologies of the films depend on the ratio between Pr and Ta dopants. From ultraviolet-visible(UV-Vis) spectrophotometer measurements, it is shown that the transmittance value of FTO film decreases with Pr and Ta doping elements increasing. The band gap value of FTO film increases only at 1 at.% Ta doping level, it drops off with Pr and Ta doping ratio increasing at other doped FTO films. The electrical measurements indicate that the sheet resistance value of FTO film initially decreases with Pr and Ta doping ratio decreasing and then it increases with Pr and Ta doping ratio increasing. The highest value of figure of merit is obtained for 1 at.% Ta- and Pr-doped FTO film. These results suggest that Pr- and Ta-doped FTO films may be appealing candidates for TCO applications.展开更多
Intense research and refinement of the tools used in performance-based seismic engineering have been made,but the maturity and accuracy of these methods have not been adequately confirmed with actual data from the fie...Intense research and refinement of the tools used in performance-based seismic engineering have been made,but the maturity and accuracy of these methods have not been adequately confirmed with actual data from the field. The gap between the assumed characteristics of actual building systems and their idealized counterparts used for analysis is wide. When the randomly distributed flaws in buildings as they exist in urban areas and the extreme variability of ground motion patterns combine,the conventional procedures used for pushover or dynamic response history analyses seem to fall short of reconciling the differences between calculated and observed damage. For emergency planning and loss modeling purposes,such discrepancies are factors that must be borne in mind. Two relevant examples are provided herein. These examples demonstrate that consensus-based analytical guidelines also require well-idealized building models that do not lend themselves to reasonably manageable representations from field data. As a corollary,loss modeling techniques,e.g.,used for insurance purposes,must undergo further development and improvement.展开更多
Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts.Platinum supported on manganese v...Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts.Platinum supported on manganese vanadate(Pt/MnV_(2)O_(6))was prepared by microwave irradiation method and characterized using X-ray diffraction,Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,scanning electron microscopy with energy dispersive spectroscopy,and transmission electron microscopy.The borohydride oxidation reaction(BOR)on Pt/MnV_(2)O_(6) was studied in highly alkaline media using voltammetry,chronoamperometry,and electrochemical impedance spectroscopy.BOR electrocatalytic activity of Pt/MnV_(2)O_(6) was also compared with that of commercial Pt/C(46 wt%Pt)electrocatalyst.The apparent activation energy of BOR at Pt/MnV_(2)O_(6) was estimated to be 32 k J mol^(-1) and the order of reaction to be 0.51,indicating that borohydride hydrolysis proceeds in parallel with its oxidation.Long-term stability of Pt/MnV_(2)O_(6) under BOR typical conditions was observed.A laboratory-scale direct borohydride fuel cell assembled with a Pt/MnV_(2)O_(6) anode reached a specific power of 274 W g^(-1).Experimental results on Pt/MnV_(2)O_(6) were complemented by DFT calculations,which indicated good adherence of Pt to MnV_(2)O_(6),beneficial for electrocatalyst stability.展开更多
Basidiomata of Cortinarius were collected during the field studies in 2019 and identified based on both morphological and molecular data.Three Cortinarius species viz.Cortinarius cadi-aguirrei,C.cinnamoviolaceus and C...Basidiomata of Cortinarius were collected during the field studies in 2019 and identified based on both morphological and molecular data.Three Cortinarius species viz.Cortinarius cadi-aguirrei,C.cinnamoviolaceus and C.variegatus are recorded for the first time from Turkey.Full descriptions,color figures,a simple phylogenetic tree and a short discussion are provided here.展开更多
We report comparatively on fabrication of two-section ridge-waveguide tapered 3 quantum well (QW) InGaAsP/InP (1300 nm) and 5 QW AlGaInAs/InP (1550 nm) diode lasers. Gas mixtures of CCl2F2/O2 and H2/CH4 were used to f...We report comparatively on fabrication of two-section ridge-waveguide tapered 3 quantum well (QW) InGaAsP/InP (1300 nm) and 5 QW AlGaInAs/InP (1550 nm) diode lasers. Gas mixtures of CCl2F2/O2 and H2/CH4 were used to form ridge-waveguide on the lasers with InP-based material structures. As known, chlorine- and hydro-carbon based gases are used to fabricate ridge-waveguide structures. Here, we show the difference between the structures obtained by using the both gas mixtures in which surface and sidewall structures as well as performance of the lasers were analysed using scanning electron microscopy. It is demonstrated that gas mixtures of CCl2F2/O2 highly deteriorated the etched structures although different flow rates, rf powers and base pressures were tried. We also show that the structures etched with H2/CH4 gas mixtures produced much better results that led to the successful fabrication of two-section devices with ridge-waveguide. The lasers fabricated using H2/CH4 were characterized using output power-current (P-I) and spectral results.展开更多
Increasing air pollution around the world causes many problems,especially in the field of health.Air pollution affects not only human health but also other living things health.The factors that cause air pollution the...Increasing air pollution around the world causes many problems,especially in the field of health.Air pollution affects not only human health but also other living things health.The factors that cause air pollution the most are heating,industry,and transportation.Many countries in the world carry out various studies to reduce the effect of these factors on air pollution.Especially in the field of transportation,studies have been quite a lot in recent years.In this study,air pollution caused by transportation in Erzurum,Turkey has investigated.Emission amounts of NO_(X),PM_(10),and SO_(2) values have calculated according to the types of vehicles in the city.Then,the amount of emissions from transportation in the total sector has revealed.The transportation structure of the city has examined in general terms and the missing aspects in terms of pedestrian transportation have revealed.Finally,some solution proposals aiming to encourage the use of pedestrian transportation and micro mobility vehicles in order to reduce motor land vehicles are presented.展开更多
In this study, the applicability of plasma nitriding treatment in the production of non-magnetic and corrosion resistant layer on 316L stainless steel implant material was investigated. 316L stainless steel substrates...In this study, the applicability of plasma nitriding treatment in the production of non-magnetic and corrosion resistant layer on 316L stainless steel implant material was investigated. 316L stainless steel substrates were plasma nitrided at temperatures of 350 ℃, 375 ℃, 400 ℃, 425 ℃ and 450 ℃ for 2 h in a gas mixture of 50% N2-50% H2, respectively. It was determined that the treatment temperature is the most important factor on the properties of the corrosion resistant layer of 316L stainless steel. The results show that s-phase formed at the temperatures under 400 ℃, and at the temperatures above 400 ℃, instead of s-phase, CrN and y'-Fe4N phases were observed in the modified layer. The electrical resistivity and surface roughness of the modified layer increase with treatment temperature. Under 400 ℃ the corrosion resistance increased with the temperature, above 400 ℃ it decreased with the increase in treatment temperature. It was analyzed that the electrical resistivity and the soft (ideal) ferro- magnetic properties of 316L stainless steel increased with treatment temperature during nitriding treatment. Also, plasma ni- triding at low temperatures provided magnetic behavior close to the ideal untreated 316L stainless steel.展开更多
In this study, CoCrMo alloy was oxidized in plasma environment at the temperatures of 600 ℃ to 800 ℃ for 1 h to 5 h with 100% 02 gas and its tribological behavior was investigated. After the plasma oxidizing process...In this study, CoCrMo alloy was oxidized in plasma environment at the temperatures of 600 ℃ to 800 ℃ for 1 h to 5 h with 100% 02 gas and its tribological behavior was investigated. After the plasma oxidizing process, the compound and diffusion layers were formed on the surface. XRD results show that Cr203, a-Co and ε-Co phases diffracted from the modified layers after plasma oxidizing. The untreated and treated CoCrMo samples were subjected to wear tests both in dry and simulated body fluid conditions, and normal loads of 2 N and 10 N were used. For the sliding wear test, alumina balls were used as counter materials. It was observed that the wear resistance of CoCrMo alloy was increased after the plasma oxidizing process. The lowest wear rate was obtained from the samples that were oxidized at 800 ℃ for 5 h. It was detected that both wear environment and load have significant effects on the wear behavior of this alloy, and the wear resistance of oxidized CoCrMo alloy is higher when oxide-based counterface is used. The wear rates of both untreated and plasma oxidized samples increase under high loads.展开更多
TiO2 films including different amounts of Ag obtained by sol-gel method on commercially pure titanium (CP-Ti) and the corrosion properties of Ag-doped TiO2 films were investigated by potentiodynamic polarisation and...TiO2 films including different amounts of Ag obtained by sol-gel method on commercially pure titanium (CP-Ti) and the corrosion properties of Ag-doped TiO2 films were investigated by potentiodynamic polarisation and Electrochemical ImpedanceSpectroscopy (EIS) tests in Simulated Body Fluid (SBF) solution. The results were compared with untreated and un-doped samples. Surface characterizations before and after the corrosion tests were performed by the Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. It was observed that Ag-doping for TiO2 films improved the corrosion resistance when compared with untreated and un-doped TiO2 film coated samples. The highest corrosion resistance was obtained from Ag-doped samples coated with a solution of 0.05 M Ag.展开更多
Thermostat as a part of engine cooling system has a significant role in the shortening warm-up time and regulating the engine in proper temperature to approach optimal performance.Whereas,there is not adequate researc...Thermostat as a part of engine cooling system has a significant role in the shortening warm-up time and regulating the engine in proper temperature to approach optimal performance.Whereas,there is not adequate research on this part of the cooling system and its responsibility.Considering this gap and also being used in large scale,this study is intended to evaluate performance and reflex of the wax type thermostat in different engine working conditions.In this regard,performance of engine cooling system was investigated in various engine speeds and loads to reveal positive and negative influences of thermostat on engine cooling efficiency and engine performance.According to observed results,warm-up period and fuel consumption decrease by using a thermostat.On the other hand,however,the temperature oscillation of coolant fluid passing through engine increases sharply,which causes a disruption in the regulating engine temperature and also a possibility of the fluid boiling rises in some regions of the engine that increases the risk of damage in the engine parts.Engine temperature,fuel consumption,warm-up duration and emissions were provided and compared in two operation modes,with and without thermostat.展开更多
Selective Laser Melting(SLM),one of the metal additive manufacturing methods in the powder bed,is frequently used in the production of 316L stainless steel biomaterial.In this study,the effect of duplex surface modifi...Selective Laser Melting(SLM),one of the metal additive manufacturing methods in the powder bed,is frequently used in the production of 316L stainless steel biomaterial.In this study,the effect of duplex surface modification(metal additive manufacturing and plasma oxidizing)on the corrosion resistance of 316L was investigated.Ti6Al4V layer was formed by additive manufacturing on 316L produced by selective laser melting method.The obtained layered Ti6Al4V/316L samples were oxidized by plasma at 650℃–750℃ and 1 h–4 h parameter conditions.TiO_(2)ceramic layer was formed on the Ti6Al4V/316L structure by plasma oxidation process in several layer thicknesses.Corrosion properties of the TiO_(2)layer were determined by Open Circuit Potential(OCP),potentiodynamic polarization,and Electrochemical Impedance Spectroscopy(EIS)tests in Simulated Body Fluid(SBF)solution.Also,the surface characterizations of the samples were determined by the Vickers micro-hardness tester,Scanning Electron Microscopy(SEM),and X-Ray Diffractometer(XRD)analysis.From the results,it was obtained that the corrosion resistance of the plasma oxidized was higher than the untreated 316L and layered Ti6Al4V/316L samples.The best corrosion resistance was obtained under the 750℃ and 4 h parameter conditions because of the increasing plasma oxidizing time and temperature.展开更多
TiO2-SiO2 composite films were produced on commercially pure titanium (CP-Ti) substrate by a sol-gel method to in- vestigate the behavior of sol aging time and its potential effects on the structural and electrochem...TiO2-SiO2 composite films were produced on commercially pure titanium (CP-Ti) substrate by a sol-gel method to in- vestigate the behavior of sol aging time and its potential effects on the structural and electrochemical properties of composite coatings. Anatase-TiO2 and quartz-SiO2 peaks were observed on all composite coated samples according to XRD results. It was observed that the average grain size increased with sol aging time. Also, the average smallest grain size was seen at composite coatings prepared from unaged sol according to the width of the peaks. Electrochemical behavior of coated samples was mainly investigated by potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) in Simulated Body Fluid (SBF) solution. In corrosion tests, the composite coatings showed better anti-corrosion behavior than that of uncoated samples. In addition, the corrosion properties of the composite films were considerably affected by sol aging time. Corrosion resistance of coatings decreased with increasing aging time and the best result was obtained from composite coatings prepared from unaged sol.展开更多
文摘The Pr and Ta separately doped FTO(10 at.% F incorporated Sn O2) films are fabricated via spray pyrolysis. The microstructural, topographic, optical, and electrical features of fluorine-doped TO(FTO) films are investigated as functions of Pr and Ta dopant concentrations. The x-ray diffraction(XRD) measurements reveal that all deposited films show polycrystalline tin oxide crystal property. FTO film has(200) preferential orientation, but this orientation changes to(211) direction with Pr and Ta doping ratio increasing. Atomic force microscopy(AFM) and scanning electron microscopy(SEM) analyses show that all films have uniform and homogenous nanoparticle distributions. Furthermore, morphologies of the films depend on the ratio between Pr and Ta dopants. From ultraviolet-visible(UV-Vis) spectrophotometer measurements, it is shown that the transmittance value of FTO film decreases with Pr and Ta doping elements increasing. The band gap value of FTO film increases only at 1 at.% Ta doping level, it drops off with Pr and Ta doping ratio increasing at other doped FTO films. The electrical measurements indicate that the sheet resistance value of FTO film initially decreases with Pr and Ta doping ratio decreasing and then it increases with Pr and Ta doping ratio increasing. The highest value of figure of merit is obtained for 1 at.% Ta- and Pr-doped FTO film. These results suggest that Pr- and Ta-doped FTO films may be appealing candidates for TCO applications.
文摘Intense research and refinement of the tools used in performance-based seismic engineering have been made,but the maturity and accuracy of these methods have not been adequately confirmed with actual data from the field. The gap between the assumed characteristics of actual building systems and their idealized counterparts used for analysis is wide. When the randomly distributed flaws in buildings as they exist in urban areas and the extreme variability of ground motion patterns combine,the conventional procedures used for pushover or dynamic response history analyses seem to fall short of reconciling the differences between calculated and observed damage. For emergency planning and loss modeling purposes,such discrepancies are factors that must be borne in mind. Two relevant examples are provided herein. These examples demonstrate that consensus-based analytical guidelines also require well-idealized building models that do not lend themselves to reasonably manageable representations from field data. As a corollary,loss modeling techniques,e.g.,used for insurance purposes,must undergo further development and improvement.
基金the Ministry of Education,Science and Technological Development of Republic of Serbia for support within project no.451–03–68/2020–14/200146Funda??o para a Ciência e a Tecnologia(FCT,Portugal)for contract no.IF/01084/2014/CP1214/CT0003 under IF2014 Programme(D.M.F.Santos)and no.IST-ID/156–2018(B.?ljuki?)+1 种基金sponsored in part by the NATO Science for Peace and Security Programme under grant G5729(I.A.Pa?ti and B.?ljuki?)the support from the Carl Tryggers Foundation for Scientific Research(grant no.18:177)。
文摘Problems associated with carbon support corrosion under operating fuel cell conditions require the identification of alternative supports for platinum-based nanosized electrocatalysts.Platinum supported on manganese vanadate(Pt/MnV_(2)O_(6))was prepared by microwave irradiation method and characterized using X-ray diffraction,Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,scanning electron microscopy with energy dispersive spectroscopy,and transmission electron microscopy.The borohydride oxidation reaction(BOR)on Pt/MnV_(2)O_(6) was studied in highly alkaline media using voltammetry,chronoamperometry,and electrochemical impedance spectroscopy.BOR electrocatalytic activity of Pt/MnV_(2)O_(6) was also compared with that of commercial Pt/C(46 wt%Pt)electrocatalyst.The apparent activation energy of BOR at Pt/MnV_(2)O_(6) was estimated to be 32 k J mol^(-1) and the order of reaction to be 0.51,indicating that borohydride hydrolysis proceeds in parallel with its oxidation.Long-term stability of Pt/MnV_(2)O_(6) under BOR typical conditions was observed.A laboratory-scale direct borohydride fuel cell assembled with a Pt/MnV_(2)O_(6) anode reached a specific power of 274 W g^(-1).Experimental results on Pt/MnV_(2)O_(6) were complemented by DFT calculations,which indicated good adherence of Pt to MnV_(2)O_(6),beneficial for electrocatalyst stability.
基金This work was financed by the Trabzon University(TAP:20TAP00123)。
文摘Basidiomata of Cortinarius were collected during the field studies in 2019 and identified based on both morphological and molecular data.Three Cortinarius species viz.Cortinarius cadi-aguirrei,C.cinnamoviolaceus and C.variegatus are recorded for the first time from Turkey.Full descriptions,color figures,a simple phylogenetic tree and a short discussion are provided here.
基金the financial support of TUB-ITAK via Project 107E163.
文摘We report comparatively on fabrication of two-section ridge-waveguide tapered 3 quantum well (QW) InGaAsP/InP (1300 nm) and 5 QW AlGaInAs/InP (1550 nm) diode lasers. Gas mixtures of CCl2F2/O2 and H2/CH4 were used to form ridge-waveguide on the lasers with InP-based material structures. As known, chlorine- and hydro-carbon based gases are used to fabricate ridge-waveguide structures. Here, we show the difference between the structures obtained by using the both gas mixtures in which surface and sidewall structures as well as performance of the lasers were analysed using scanning electron microscopy. It is demonstrated that gas mixtures of CCl2F2/O2 highly deteriorated the etched structures although different flow rates, rf powers and base pressures were tried. We also show that the structures etched with H2/CH4 gas mixtures produced much better results that led to the successful fabrication of two-section devices with ridge-waveguide. The lasers fabricated using H2/CH4 were characterized using output power-current (P-I) and spectral results.
文摘Increasing air pollution around the world causes many problems,especially in the field of health.Air pollution affects not only human health but also other living things health.The factors that cause air pollution the most are heating,industry,and transportation.Many countries in the world carry out various studies to reduce the effect of these factors on air pollution.Especially in the field of transportation,studies have been quite a lot in recent years.In this study,air pollution caused by transportation in Erzurum,Turkey has investigated.Emission amounts of NO_(X),PM_(10),and SO_(2) values have calculated according to the types of vehicles in the city.Then,the amount of emissions from transportation in the total sector has revealed.The transportation structure of the city has examined in general terms and the missing aspects in terms of pedestrian transportation have revealed.Finally,some solution proposals aiming to encourage the use of pedestrian transportation and micro mobility vehicles in order to reduce motor land vehicles are presented.
文摘In this study, the applicability of plasma nitriding treatment in the production of non-magnetic and corrosion resistant layer on 316L stainless steel implant material was investigated. 316L stainless steel substrates were plasma nitrided at temperatures of 350 ℃, 375 ℃, 400 ℃, 425 ℃ and 450 ℃ for 2 h in a gas mixture of 50% N2-50% H2, respectively. It was determined that the treatment temperature is the most important factor on the properties of the corrosion resistant layer of 316L stainless steel. The results show that s-phase formed at the temperatures under 400 ℃, and at the temperatures above 400 ℃, instead of s-phase, CrN and y'-Fe4N phases were observed in the modified layer. The electrical resistivity and surface roughness of the modified layer increase with treatment temperature. Under 400 ℃ the corrosion resistance increased with the temperature, above 400 ℃ it decreased with the increase in treatment temperature. It was analyzed that the electrical resistivity and the soft (ideal) ferro- magnetic properties of 316L stainless steel increased with treatment temperature during nitriding treatment. Also, plasma ni- triding at low temperatures provided magnetic behavior close to the ideal untreated 316L stainless steel.
文摘In this study, CoCrMo alloy was oxidized in plasma environment at the temperatures of 600 ℃ to 800 ℃ for 1 h to 5 h with 100% 02 gas and its tribological behavior was investigated. After the plasma oxidizing process, the compound and diffusion layers were formed on the surface. XRD results show that Cr203, a-Co and ε-Co phases diffracted from the modified layers after plasma oxidizing. The untreated and treated CoCrMo samples were subjected to wear tests both in dry and simulated body fluid conditions, and normal loads of 2 N and 10 N were used. For the sliding wear test, alumina balls were used as counter materials. It was observed that the wear resistance of CoCrMo alloy was increased after the plasma oxidizing process. The lowest wear rate was obtained from the samples that were oxidized at 800 ℃ for 5 h. It was detected that both wear environment and load have significant effects on the wear behavior of this alloy, and the wear resistance of oxidized CoCrMo alloy is higher when oxide-based counterface is used. The wear rates of both untreated and plasma oxidized samples increase under high loads.
文摘TiO2 films including different amounts of Ag obtained by sol-gel method on commercially pure titanium (CP-Ti) and the corrosion properties of Ag-doped TiO2 films were investigated by potentiodynamic polarisation and Electrochemical ImpedanceSpectroscopy (EIS) tests in Simulated Body Fluid (SBF) solution. The results were compared with untreated and un-doped samples. Surface characterizations before and after the corrosion tests were performed by the Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analysis. It was observed that Ag-doping for TiO2 films improved the corrosion resistance when compared with untreated and un-doped TiO2 film coated samples. The highest corrosion resistance was obtained from Ag-doped samples coated with a solution of 0.05 M Ag.
基金This work was supported by The Scientific and Technological Research Council of Turkey(TUBITAK,project no 315M260)。
文摘Thermostat as a part of engine cooling system has a significant role in the shortening warm-up time and regulating the engine in proper temperature to approach optimal performance.Whereas,there is not adequate research on this part of the cooling system and its responsibility.Considering this gap and also being used in large scale,this study is intended to evaluate performance and reflex of the wax type thermostat in different engine working conditions.In this regard,performance of engine cooling system was investigated in various engine speeds and loads to reveal positive and negative influences of thermostat on engine cooling efficiency and engine performance.According to observed results,warm-up period and fuel consumption decrease by using a thermostat.On the other hand,however,the temperature oscillation of coolant fluid passing through engine increases sharply,which causes a disruption in the regulating engine temperature and also a possibility of the fluid boiling rises in some regions of the engine that increases the risk of damage in the engine parts.Engine temperature,fuel consumption,warm-up duration and emissions were provided and compared in two operation modes,with and without thermostat.
基金the Erzurum Technical University High Technology Research and Application Centre(ETÜ-YÜTAM)for their valuable contribution.
文摘Selective Laser Melting(SLM),one of the metal additive manufacturing methods in the powder bed,is frequently used in the production of 316L stainless steel biomaterial.In this study,the effect of duplex surface modification(metal additive manufacturing and plasma oxidizing)on the corrosion resistance of 316L was investigated.Ti6Al4V layer was formed by additive manufacturing on 316L produced by selective laser melting method.The obtained layered Ti6Al4V/316L samples were oxidized by plasma at 650℃–750℃ and 1 h–4 h parameter conditions.TiO_(2)ceramic layer was formed on the Ti6Al4V/316L structure by plasma oxidation process in several layer thicknesses.Corrosion properties of the TiO_(2)layer were determined by Open Circuit Potential(OCP),potentiodynamic polarization,and Electrochemical Impedance Spectroscopy(EIS)tests in Simulated Body Fluid(SBF)solution.Also,the surface characterizations of the samples were determined by the Vickers micro-hardness tester,Scanning Electron Microscopy(SEM),and X-Ray Diffractometer(XRD)analysis.From the results,it was obtained that the corrosion resistance of the plasma oxidized was higher than the untreated 316L and layered Ti6Al4V/316L samples.The best corrosion resistance was obtained under the 750℃ and 4 h parameter conditions because of the increasing plasma oxidizing time and temperature.
文摘TiO2-SiO2 composite films were produced on commercially pure titanium (CP-Ti) substrate by a sol-gel method to in- vestigate the behavior of sol aging time and its potential effects on the structural and electrochemical properties of composite coatings. Anatase-TiO2 and quartz-SiO2 peaks were observed on all composite coated samples according to XRD results. It was observed that the average grain size increased with sol aging time. Also, the average smallest grain size was seen at composite coatings prepared from unaged sol according to the width of the peaks. Electrochemical behavior of coated samples was mainly investigated by potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) in Simulated Body Fluid (SBF) solution. In corrosion tests, the composite coatings showed better anti-corrosion behavior than that of uncoated samples. In addition, the corrosion properties of the composite films were considerably affected by sol aging time. Corrosion resistance of coatings decreased with increasing aging time and the best result was obtained from composite coatings prepared from unaged sol.