共查询到20条相似文献,搜索用时 31 毫秒
1.
Muhammad Yasir Cheng Zhang Wei Wang Zhi-Wei Zhang Lin Liu 《Journal of Thermal Spray Technology》2016,25(8):1554-1560
Although corrosion and friction/wear behavior of Fe-based amorphous coatings and their composites has been extensively studied during the past decade, there is very limited work related to tribocorrosion behavior. In this paper, the tribocorrosion behavior of a Fe-based amorphous composite coating reinforced with 20 wt.% Al2O3 particles was investigated in a 3.5% NaCl solution on a ball-on-disk tester and was compared to the monolithic amorphous coating and 316L stainless steel (SS). The results showed that the amorphous composite coating exhibited the highest tribocorrosion resistance among the three materials tested, as evidenced by the lowest coefficient of friction (~0.3) and tribocorrosion wear rate (~1.2 × 10?5 mm3/N·m). In addition, potentiodynamic polarization measurements before and during tribocorrosion testing demonstrated that corrosion resistance of the amorphous composite coating was not influenced so much by mechanical loading compared to the amorphous coating and the 316L SS. Observations on the worn surface revealed a corrosion-wear- and oxidational-wear-dominated tribocorrosion mechanism for the composite coatings. The excellent tribocorrosion resistance of the composite coating results from the effect of chemically stable Al2O3 phase which resists oxidation and delamination during sliding, along with poor wettability with corrosive NaCl droplets. 相似文献
2.
S. Sadreddini S. Rahemi Ardakani H. Rassaee 《Journal of Materials Engineering and Performance》2017,26(5):2032-2039
In the present work, nano-composites of Ni-P-SiO2-Al2O3 were coated on AZ91HP magnesium alloy. The surface morphology of the nano-composite coating was studied by field emission scanning electron microscopy (FESEM). The amount of SiO2 in the coating was determined by energy-dispersive analysis of x-ray (EDX), and the crystalline structure of the coating was examined by x-ray diffractometer (XRD). All the experiments concerning the corrosion behavior of the coating carried out in 3.5 wt.% NaCl solution and evaluated by electrochemical impedance spectroscopy (EIS) and polarization technique. The results showed that an incorporation of SiO2 and Al2O3 in Ni-P coating at the SiO2 concentration of 10 g/Land 14 g/LAl2O3 led to the lowest corrosion rate (i corr = 1.3 µA/cm2), the most positive E corr and maximum microhardness (496 VH). Furthermore, Ni-P-SiO2-Al2O3 nano-composite coating possesses less porosity than that in Ni-P coating, resulting in improving corrosion resistance. 相似文献
3.
Jabril A. Khamaj 《Protection of Metals and Physical Chemistry of Surfaces》2016,52(5):886-893
The study on the corrosion behavior of the composite and evaluation of surface modification technique are of importance since the addition of reinforcement particles affects the continuity of inherent oxide layer on the matrix and hence its corrosion resistance. The present study deals with the investigations of effect of ceramic coating on the corrosion behavior of 6061 Al/SiCP (20 volume % reinforcement) composite in 3.5 M NaCl solution at high temperatures namely 30 and 40°C using potentiodynamic polarization technique and cyclic polarization plots. Aluminum coating by magnetron sputtering technique is employed on the composite and it is subjected to heat treatment at 200°C for duration of 2 h for the alumina formation. The alumina coating formed on the composite surface acts as corrosion protective coating. The potentiodynamic polarization technique is used to determine the corrosion rate of the composite specimen with and without ceramic coating in the corrosion media. The cyclic polarization technique is used to study the pitting behavior of the composite with and without ceramic coating. The microstructural analysis is carried out using scanning electron microscopy (SEM). X-RD analysis shows the amorphous nature of Alumina coating obtained on the composite. The results show that the peak aged composite is more prone to corrosion among the aged group of composites but when coated with alumina shows a vast improvement in pitting nucleation resistance even at high temperatures. 相似文献
4.
Plasma electrolytic oxidation (PEO) coatings in the aluminate-silicate-based mixture electrolyte solution with different duty cycles were successfully applied on Mg alloy. The corrosion behavior of the samples was evaluated by water contact angle test, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and immersion tests. Hydrophobic PEO coating could be obtained by adjusting the duty cycle of the applied electric signal. This coating considerably diminished the Mg dissolution and could enhance the impedance values of Mg alloy in 3.5 wt % NaCl solution. However, the surface of other PEO coated samples showed more hydrophilic properties compared to that of the uncoated sample. Dense structure of the modified PEO multiphase (including Mg2SiO4, MgO and MgAl2O4 phases) coating and also its appropriate thickness provided an effective barrier to remarkably delay corrosive solution penetration into the PEO coating. This phenomenon led to major decrease in anodic current density of alloy in chloride solution. 相似文献
5.
The pitting corrosion behavior of the underaged (UA), peakaged (PA) and overaged (OA) T6 AA2024/0, 8, 14, 19, 24 vol.% 40 μm SiCp(particles) composites was studied. The processing route used for the materials was the compocasting technique. Corrosion potentials (Ecor), pitting potentials (Epit) as well as protection potentials (Eprot) were extracted from Double Cycle Polarization (DCP) curves contacted in aerated 3.5 wt.% NaCl aqueous solution. In addition 40 days immersion tests carried out and weight loss curves as well as total pit depth measurements were acquired. Pitting initiation and propagation as the main corrosion mechanism was driven by the aging kinetics which is ruled by the reduction in the retained vacancy concentration and at the same time by the increase in dislocation density as SiCp volume fraction increases. Thus, alteration in pitting behavior among composites of different SiCp content took place, although their ageing status was exactly the same. 相似文献
6.
Terence P. Savas Allen Yi-Lan Wang James C. Earthman 《Journal of Materials Engineering and Performance》2003,12(2):165-171
The effect of heat treatment on the corrosion resistance of 440C stainless steel was investigated in a 20% HNO3 + 2.5% Na2Cr2O7 solution using electrochemical noise (ECN) measurements, electrochemical impedance spectroscopy (EIS), and scanning electron
microscopy (SEM) examinations. The noise resistance (Rn), which has been found to be inversely related to the localized corrosion rate, was measured to be 5.7E + 08 Ω-cm2, 4.2E + 08 Ω-cm2, and 3.7E + 04 Ω-cm2 for the oil-quenched, air-quenched, and vacuum furnace cooled (VFC) samples, respectively, after 1200 s exposures. The Rn for all heat treat conditions stabilized within a range of 1.0E + 07 Ω-cm2 to 3.2E + 08 Ω-cm2 after 2 h exposures. The EIS response showed a polarization resistance (R
p) on the order of 6.6E + 04 Ω-cm2, 5.3E + 04 Ω-cm2, and 1.1E + 04 Ω-cm2 for the oil-quenched, air-quenched, and VFC samples, respectively, after 2 h exposures. The EIS data are in good agreement
with ECN data and indicate that after longer exposures, general corrosion mechanisms dominate and the corrosion rates are
comparable. SEM examinations of specimens subjected to 1200 s exposures revealed that severity of pitting and intergranular
corrosion damage was consistent with trends in the Rn data. Specifically, the electrochemical noise data as well as SEM examinations of specimens revealed a higher localized
corrosion resistance of the hardened specimens during the early stages of passivation. This greater resistance to localized
corrosion can be attributed to an increased stability of the natural passive film resulting from a higher concentration of
chromium atoms in solution for the martensite phase. 相似文献
7.
S. Rajasekaran N. K. Udayashankar Jagannath Nayak 《Surface Engineering and Applied Electrochemistry》2011,47(2):176-180
One of the main drawbacks of 6061 Al/SiCP composite is its poor pitting corrosion resistance in the aggressive environment containing chloride ions, such as seawater, for example. The present article deals with the investigations of effects of aging on the corrosion behavior of 6061 Al/SiCP composite and of the heat treatment on the pitting corrosion resistance of 6061 Al/SiCP composite coated by cerium oxide prepared by chemical bath technique. Potentiodynamic polarization test was used to study the corrosion behavior of cerium oxide coatings in 3.5N NaCl solution. The microstructure of cerium oxide was examined by scanning electron microscopy (SEM) and the formed phases were identified by X-ray diffraction (XRD). The pitting corrosion resistance of the cerium oxide coating was found to be improved after heat treatment at 300°C for 30 min. 相似文献
8.
9.
P. Babadi S. Sadreddini F. Mohsenifar M. Roshani 《Protection of Metals and Physical Chemistry of Surfaces》2016,52(2):249-253
In this study, the effect of electrophoretic voltage changes on Ni—Al2O3 nano-composite coating via two step process electrophoretic, and electrochemically on 1100 Al substrate on morphology, corrosion and wear behaviour were studied. In the first step of deposition for determining the optimum amount of Teri Ethanol Amin activator in electrophoretic suspension Transmission Electron Microscopy (TEM) was used. The amount of alumina particles, Nickel ions in the coating and morphology were studied by Energy-dispersive X-ray spectroscopy (EDX) and Field-Emission Electron Microscopy (FESEM). Nanoparticles distribute more homogenous in deposit within using 40 V voltage. Corrosion behaviour of coating was investigated by polarization technique in 3.5 wt % NaCl which shows a decrease in corrosion current from 13.7 μA/cm2 to 1.46 μA/cm2 versus bare sample. 相似文献
10.
《Corrosion Science》1999,41(3):529-545
The influence of the heat treatments on the corrosion behaviour of three aluminium matrix composites (AA6061/Al2O3/10p–20p and AA7005/Al2O3/10p) has been analysed in an aerated 3.5% sodium chloride solution. Corrosion potentials were determinated in a 3.5% sodium chloride solution (NaCl) using the ASTM standard G69-81 [1]. The galvanic series and the pitting potentials were calculated in this medium for all composites. The following heat treatments were applied on the base composites: (a) as-received state (T4), (b) T6 treatment, (c) an annealing, consisting of a solution stage at 560°C for 3 h for the AA6061 MMC and (d) an annealing at 482°C for 2 h for the AA7005/Al2O3/10p, followed by a cooling in the atmosphere furnace. The localised corrosion susceptibility of each material and for each heat treatment were analysed by measurement of the cyclic potentiodynamic polarization. Optical microscopy and SEM metallographic studies were carried out on the samples, before and after corrosion tests, to determine the influence of the microstructural changes during heat treatments on the corrosion behaviour. 相似文献
11.
The influence of silicon carbide particles (SiCp) addition on the corrosion behavior of Al-Cu alloy (2014) was evaluated in 3.5% NaCl solution at 30 °C using microstrucural and electrochemical measurements. Addition of 10 wt.% SiCp to the base alloy is found to increase its corrosion resistance considerably. Incorporation of SiCp beyond this proportion leads to an increase in corrosion rate of the synthesized composites. Addition of 25 wt.% SiCp to base alloy decreases corrosion resistances considerably. Microstructural studies reveal the agglomeration of SiC particles in the composites. This results an increase of corrosion reaction with the increase of SiC particles in the composites. EIS measurement indicates the occurrence of adsorption/diffusion phenomena at the interfaces of the composites that ultimately initiate the localized or pitting corrosion. 相似文献
12.
The corrosion behavior of an amorphous Co69Fe4.5Ni1.5Si10B15 alloy ribbon was examined as a function of solution temperature (15 °C to 55 °C) and pH (3 to 11). The results of potentiodynamic
polarization tests in H2SO4 solution, NaCl solution, and HCl + NaOH solution at various levels of pH showed that the corrosion
resistance for the alloy ribbon significantly deteriorated with increasing temperature and decreasing pH for given conditions.
The Co69Fe4.5Ni1.5Si10B15 alloy was actively dissolved in solutions at pH 3 to 9 but passivated in a solution at pH 11. By comparison of the corrosion
behaviors of Co69Fe4.5(Nb,Cr,Ni)1.5Si10B15 alloys in the solution at pH 11, Ni was considered to contribute less in improving the corrosion resistance of the alloy
than did Cr and Nb. 相似文献
13.
The purpose of this study was to investigate the electrochemical corrosion properties of flame-sprayed Al and Al/(5, 10, 15)% Ti3SiC2 coatings in a 3.5% NaCl solution. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used for analyzing the microstructural characteristics of the coatings. For examining the corrosion behavior of the coatings, a potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) were used. After the potentiodynamic polarization test, the SEM micrograph of coatings indicated that Ti3SiC2 particles played a significant role in pitting corrosion. The results of potentiodynamic polarization tests revealed that Al/Ti3SiC2 coating is nobler than that of the pure aluminum coating. On the contrary, the addition of Ti3SiC2 particles reduced the process of thickening the passive layer. The results of the EIS tests demonstrated that the presence of Ti3SiC2 particles significantly enhances the corrosion resistance of the coatings. 相似文献
14.
F. B. Destro M. Cilense M. P. Nascimento F. González Garcia L. R. O. Hein A. Z. Simões 《Protection of Metals and Physical Chemistry of Surfaces》2016,52(1):104-110
This study examines the effect of film thickness ranging from 230 to 404 nm on the corrosion resistance of Nb2O5 thin films grown by chemical solution deposition. The films were characterized to obtain the relationships between the deposition parameters and the most relevant physical properties (structural, surface morphology and corrosion resistance). From X-ray diffraction and XPS analyses we can conclude that the films were stoichiometric Nb2O5 and crystalline. The internal strain and morphology of the film changes as the number of layers increases indicating a thickness dependent grain size. The surface roughness, corrosion resistance were also affected by the film thickness. Electrochemical impedance spectroscopy (EIS) shows that the thicker film have higher passive and charge transfer resistance than the control samples. These results coating layer of Nb2O5 improves the corrosion resistance on an API 5L X80 steel alloy due to the formation of a film on the surface. 相似文献
15.
Annegret Potthoff Robert Kratzsch Maria Barbosa Nick Kulissa Oliver Kunze Filofteia-Laura Toma 《Journal of Thermal Spray Technology》2018,27(4):710-717
Compositions in the system Cr2O3-TiO2-Al2O3 are among the most used ceramic materials for thermally sprayed coating solutions. Cr2O3 coatings present good sliding wear resistance; Al2O3 coatings show excellent insulation behavior and TiO2 striking corrosion properties. In order to combine these properties, coatings containing more than one oxide are highly interesting. The conventional spraying process is limited to the availability of binary feedstock powders with defined compositions. The use of suspensions offers the opportunity for tailor-made chemical compositions: within the triangle of Cr2O3-TiO2-Al2O3, each mixture of oxides can be created. Criteria for the selection of raw materials as well as the relevant aspects for the development of binary suspensions in the Cr2O3-TiO2-Al2O3 system to be used as feedstock for thermal spraying are presented. This formulation of binary suspensions required the development of water-based single-oxide suspensions with suitable behavior; otherwise, the interaction between the particles while mixing could lead up to a formation of agglomerates, which affect both the stability of the spray process and the coating properties. For the validation of this formulation procedure, binary Cr2O3-TiO2 and Al2O3-TiO2 suspensions were developed and sprayed using the S-HVOF process. The binary coatings were characterized and discussed in terms of microstructure and microhardness. 相似文献
16.
It is one of the future trends to create materials in situ by laser additive manufacturing. AlSi7Mg/nano-SiCp composites were successfully in situ prepared by selective laser melting in our previous study. After adding 2 wt% nano-SiC particles, the tensile stress and strain increased to 502.94 ± 6.40 MPa and 10.64 ± 1.06%, respectively. For the first time in the present study, we systematically studied and compared the wear performance and corrosion behavior of AlSi7Mg with its composite. We conducted the ball-on-fl at frictional wear test at room temperature, potentiodynamic polarization, electrochemical impedance spectroscopy(EIS), and the immersion corrosion tests in 3.5 wt% NaCl solution. The results showed that composite had higher wear resistance, while AlSi7Mg was more resistant to pitting corrosion. However, the further pitting corrosion of composite was restrained because of the in situ phase nano-Al_4C_3 and the residual nano-SiCp. 相似文献
17.
S. Ariharan Pradyut Sengupta Ambreen Nisar Ankur Agnihotri N. Balaji S. T. Aruna Kantesh Balani 《Journal of Thermal Spray Technology》2017,26(3):417-431
Graphite is used in high-temperature gas-cooled reactors because of its outstanding irradiation performance and corrosion resistance. To restrict its high-temperature (>873 K) oxidation, atmospheric-plasma-sprayed SiC-ZrB2-Al2O3-carbon nanotube (CNT) dual-layer coating was deposited on graphite substrate in this work. The effect of each layer was isolated by processing each component of the coating via spark plasma sintering followed by isothermal kinetic studies. Based on isothermal analysis and the presence of high residual thermal stress in the oxide scale, degradation appeared to be more severe in composites reinforced with CNTs. To avoid the complexity of analysis of composites, the high-temperature activation energy for oxidation was calculated for the single-phase materials only, yielding values of 11.8, 20.5, 43.5, and 4.5 kJ/mol for graphite, SiC, ZrB2, and CNT, respectively, with increased thermal stability for ZrB2 and SiC. These results were then used to evaluate the oxidation rate for the composites analytically. This study has broad implications for wider use of dual-layer (SiC-ZrB2/Al2O3) coatings for protecting graphite crucibles even at temperatures above 1073 K. 相似文献
18.
Farhad Batmanghelich Mohiedin Bagheri Hariri Samin Sharifi-Asl Yadollah Yaghoubinezhad Golsa Mortazavi Youngwoo Seo 《Metals and Materials International》2016,22(4):609-620
Corrosion and time–dependent oxide film growth on AA5052 Aluminum alloy in 0.25M Na2SO4 solution containing H2O2 was studied using electrochemical impedance spectroscopy, potentiodynamic polarization, chronoamperometric and open circuit potential monitoring. It was found that sequential addition of H2O2 provokes passivation of AA5052 which ultimately thickens the oxide film and brings slower corrosion rates for AA5052. H2O2 facilitates kinetics of oxide film growth on AA 5052 at 25° and 60 °C which is indicative of formation of a thick barrier film that leads to an increment in the charge transfer resistance. Pitting incubation time increases by introduction of H2O2 accompanied by lower pitting and smoother surface morphologies. At short exposure (up to 8 h) to H2O2–containing solution, the inductive response at low frequencies predominantly determined the corrosion mechanism of AA5052. On the other hand, at prolonged exposure times (more than 24 h) to 0.25M Na2SO4+1vol% H2O2 solution, thicker oxide layers resulted in the mixed inductive–Warburg elements in the spectra. 相似文献
19.
H. Ruiz-Luna J. Porcayo-Calderon J. M. Alvarado-Orozco J. E. García-Herrera L. Martinez-Gomez L. G. Trápaga-Martínez J. Muñoz-Saldaña 《Journal of Thermal Spray Technology》2016,25(7):1330-1343
The effect of pre-oxidation treatment and surface preparation of optimized NiCoCrAlY coatings deposited by high-velocity oxygen fuel (HVOF) spraying and exposed to a low-temperature corrosive environment is reported herein. Coatings with two surface finish conditions (as-sprayed and ground) were heat treated under two different oxygen partial pressures (air and argon). The electrochemical corrosion behavior was evaluated in CO2-saturated brine via potentiodynamic polarization, polarization resistance, and electrochemical impedance measurements. The results show that the grinding process and pre-oxidation treatment in argon enhanced growth and formation of α-Al2O3 scale. The potentiodynamic polarization results show that both pre-oxidation and surface treatment had a positive influence on the corrosion resistance of the coating. The reduction of the porosity and the formation of a dense, uniform, and adherent oxide scale through pre-oxidation treatment led to an increase of the corrosion resistance due to a decrease in active sites and blocking of diffusion of reactive species into the coating. However, according to the results, complete transformation from metastable alumina phases to α-Al2O3 in addition to formation and growth of dense α-Al2O3 is required to ensure full protection of the coating and base material over long periods. 相似文献
20.
Qinglai Jiang Guorong Hu Zhongdong Peng Ke Du Yanbing Cao Daichun Tang 《稀有金属(英文版)》2009,28(6):618-623
Regular spherical chromium doped spinel lithium manganese oxides (LiCr0.04Mn1.96O4) with an average particle size of about 20 μm were prepared by the slurry spray drying process. The materials were compared
with non-spherical LiCr0.04Mn1.96O4 materials prepared by the common drying process, and all materials were characterized by X-ray diffraction (XRD), scanning
electron microscopy (SEM), laser particle analyzer and Brunauer-Emmett-Teller (BET) specific surface area test. Electrochemical
performances of these cathode materials were studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS)
and Li/LiCr0.04Mn1.96O4 battery test. The results show that the spherical active material is single spinel structure, compact, and with narrow particle
size distribution and low BET specific surface area. Compared with the non-spherical material, the spherical material prepared
by the spray drying process shows a lower electrochemical impedance, a fewer electrochemical polarization and a better charge/discharge
rate capability and capacity retention at elevated temperatures. 相似文献