Journal articles: 'Aluminum coatings'

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Lazarevic, Zorica, Vesna Miskovic-Stankovic, Zorica Kacarevic-Popovic, and Dragutin Drazic. "Epoxy coatings electrodeposited on aluminium and modified aluminium surfaces." Chemical Industry 56, no. 11 (2002): 468–72. http://dx.doi.org/10.2298/hemind0211468l.

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The corrosion behaviour and thermal stability of epoxy coatings electrodeposited on modified aluminum surfaces (anodized, phosphatized and chromatized-phosphatized aluminium) were monitored during exposure to 3% NaCl solution, using electrochemical impedance spectroscopy (EIS) and thermogravimetric analysis (TGA). Better protective properties of the epoxy coatings on anodized and chromatized-phosphatized aluminum with respect to the same epoxy coatings on aluminum and phosphatized aluminum were obtained: higher values of Rp and Rct and smaller values of Cc and Cd, from EIS, and a smaller amount of absorbed water inside the coating, from TGA. On the other hand, a somewhat lower thermal stability of these coatings was obtained (smaller values of the ipdt temperature). This behavior can be explained by the less porous structure of epoxy coatings on anodized and chromatized-phosphatized aluminum, caused by a lower rate of H2 evolution and better wet ability.

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Zhu, Sheng, Guo Feng Han, Xiao Ming Wang, Yu Xiang Liu, and Zhi Qian Wang. "Electrochemical Characteristics of TiAl Coating on Aluminum Alloy Surface by Supersonic Particles Deposition." Advanced Materials Research 1051 (October 2014): 199–203. http://dx.doi.org/10.4028/www.scientific.net/amr.1051.199.

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In this study, Ti-45Al-7Nb-4V alloy protective coating which base on γ-TiAl phase was deposited on the surface of 5803 aluminum alloy by supersonic particles deposition technology. Researchers observed the micro-structure of the TiAl alloy casting and coating by SEM, and researched the electrochemical characteristics and the galvanic corrosion between TA2 titanium alloy and 5083 aluminum alloy or TiAl alloy casting and coating by electrochemical work station. The results show that,the galvanic corrosion current between 5083 aluminium alloy and TA2 titanium alloy declines from 16.2μA to 0.27μA after TiAl protecting coatings are prepared on the substrates, besides, the corrosion susceptibility drops from E degree to A degree. It also manifests that the 5083 aluminium alloy with Ti-45Al-7Nb-4V coatings can be contacted and utilized with TA2 titanium alloy directly, which tackles the issues of gavanic corrosion prevention between aluminium alloys and titanium alloys.

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Ha, Pham Thi, Pham Thi Ly, Nguyen Van Tuan, Vo An Quan, and Le Thu Quy. "EFFECTS OF ALUMINUM PHOSPHATE CONTAINING Al2O3 NANOPARTICLES ON THE MECHANICAL PROPERTIES OF THE Al2O3-TiO2 PLASMA SPRAYED COATING." Vietnam Journal of Science and Technology 55, no. 6 (December 11, 2017): 698. http://dx.doi.org/10.15625/2525-2518/55/6/9026.

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In the present study, Al2O3-40% TiO2 composite coatings were fabricated on CT3 steel substrate by plasma spraying technique. The coatings were sealed with aluminum phosphate solution contained 5 wt.% Al2O3 nanoparticles and then heat treated at 400oC. The permeability of aluminum phosphate solution, phase composition, structure morphology, microhardness and wear resistance of the coating were studied. The study results phase composition of the coatings showed that the coatings were composed γ-Al2O3 and Al2TiO5 phase. The compounds AlPO4 and Al(PO3)3 were found in the coating sealed with aluminum phosphate. The presence of Al2O3 nanoparticles was increased the permeability of the aluminum phosphate solution into the coating. The coatings sealed with aluminum phosphate contained Al2O3 nanoparticles have lower density, higher hardness and wear resistance higher than the coating sealed with aluminum phosphate uncontain Al2O3 nanoparticles and the unsealed coating.

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Alshmri, F. "Metallic Coatings: Al-Zn Alloys." Advanced Materials Research 915-916 (April 2014): 608–11. http://dx.doi.org/10.4028/www.scientific.net/amr.915-916.608.

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Steel sheet has one major drawback, it is attacked by moisture at low temperatures and oxygen at high temperatures. Fortunately, coatings can provide protection to steel sheet from corrosion. Aluminum and aluminum zinc coatings can be applied by different methods. These are chemical vapor deposition coating (CVD), slurry coating, vacuum coating, spray coating, cladding, electroplating, electrophoresis, diffusion coatings, cementation, calorizing and hot dipping. This paper aims at providing a survey of these processes.

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Chen, Cheng Zhou, Wei Ze Wang, and Kai Di Cheng. "A Comparative Study on the Wear and Corrosion Resistance of Coatings." Applied Mechanics and Materials 853 (September 2016): 441–45. http://dx.doi.org/10.4028/www.scientific.net/amm.853.441.

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The vessel containing sulfur particles has been found failing due to the effect of corrosion and erosion by the sulfur particles. Several coatings, including zinc-aluminum coating, wear-resistance painting and two kinds of polymer, have been provided to resist the negative influence of sulfur in the present study. The wear and corrosion resistance of the selected coatings has been measured to study the performance difference. Impact test has also been done to investigate the bonding condition of coatings under the impact or bending load. The microstructure of coatings before and after wear test is observed by the Optical Microscope (OM) and Scanning Electron Microscope (SEM). The experiment results reveal that one of the polymer coatings shows the best performance in the corrosion resistance, another polymer coating’s wear resistance is better than others. The coatings are bonded well with the substrate except the zinc-aluminum coating. The performance of painting is ordinary in this investigation.

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Ho, Wei Yu, Pin Hua Hsu, and Chien Liang Lin. "Characteristics of Aluminum Chromium Nitride, and Aluminum Chromium Oxynitride Coating through Cathodic Arc Deposition." Key Engineering Materials 735 (May 2017): 70–74. http://dx.doi.org/10.4028/www.scientific.net/kem.735.70.

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Aluminum chromium nitride (AlCrN) coatings and aluminum chromium oxynitride (AlCrON) coatings were successfully fabricated through cathodic arc deposition with pulsed bias. The results indicated that both AlCrN and AlCrON coatings had a lower coefficient of friction against AISI 52100 bearing ball under dry conditions than CrN coating. The hardness of the AlCrN coating was in the range of 30 GPa, two times higher than that of the AlCrON coating. Thermogravimetric and differential scanning calorimetry analyzer (TGA/DSC) confirmed the best thermal stability of the AlCrON coating during the test.

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Zhu, Qing Jun, Kai Wang, and Xin Hong Wang. "Corrosion Behavior of Cold-Spray Aluminum Coating in Marine Environment." Advanced Materials Research 160-162 (November 2010): 364–68. http://dx.doi.org/10.4028/www.scientific.net/amr.160-162.364.

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Aluminum coatings were prepared by cold spray on mild carbon steel Q235. Scanning electron microscopy shows that the bond zone has good bonding between the substrate and the coating and the coatings consist of interlocked particles. The corrosion behaviors of the coatings in marine environment were studied by electrochemical methods. Free corrosion potentials of aluminum coatings are much lower than that of Q235. Potentiodynamic polarization measurements show that the curves of aluminum coatings have activity anodic dissolution zone, passivation zone and super-passivation zone. Corrosion morphology and energy dispersive spectrometers show that Cl- can penetrate into the coating and some of the substrate has been corroded. Corrosion only can happen on the coating surface and specific deeper sites, where Cl- can penetrate through pores. Cold spray aluminum coatings can protect the substrate from corrosion in marine environment.

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Li, Wen Sheng, and Yi Liu. "Effect of Ce on Wear Behavior of Plasma Spray Welded Novel Aluminum Bronze Coatings." Advanced Materials Research 418-420 (December 2011): 831–34. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.831.

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Aluminum bronze powders with free and 0.1wt%Ce were plasma spray welded on 45# carbon steel substrate, Effects of rare earth Ce on the microstructure and wear resistance of plasma spray welded novel aluminum bronze coatings were investigated. Tribological properties of coatings were tested on reciprocating sliding tester. Results showed that a small amount of Ce (0.1wt %) in novel aluminum bronze coating can refine the coating microstructure and the coating with 0.1wt%Ce process higher wear resistance compared to the Ce-free coating. Both of the coatings have different wear mechanisms.

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Algahtani, Ali, Essam Mahmoud, Sohaib Khan, and Vineet Tirth. "Experimental Studies on Corrosion Behavior of Ceramic Surface Coating using Different Deposition Techniques on 6082-T6 Aluminum Alloy." Processes 6, no. 12 (November 26, 2018): 240. http://dx.doi.org/10.3390/pr6120240.

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Aluminum alloys cannot be used in aggressive corrosion environments application. In this paper, three different surface coating technologies were used to coat the 6082-T6 aluminum alloy to increase the corrosion resistance, namely Plasma Electrolytic Oxidation (PEO), Plasma Spray Ceramic (PSC) and Hard Anodizing (HA). The cross-sectional microstructure analysis revealed that HA coating was less uniform compared to other coatings. PEO coating was well adhered to the substrate despite the thinnest layer among all three coatings, while the PSC coating has an additional loose layer between the coat and the substrate. X-ray diffraction (XRD) analysis revealed crystalline alumina phases in PEO and PSC coatings while no phase was detected in HA other than an aluminum element. A series of electrochemistry experiments were used to evaluate the corrosion performances of these three types of coatings. Generally, all three-coated aluminum showed better corrosion performances. PEO coating has no charge transfer under all Inductive Coupled Plasma (ICP) tests, while small amounts of Al3+ were released for both HA and PSC coatings at 80 °C. The PEO coating showed the lowest corrosion current density followed by HA and then PSC coatings. The impedance resistance decreased as the immersion time increased, which indicated that this is due to the degradation and deterioration of the protective coatings. The results indicate that the PEO coating can offer the most effective protection to the aluminum substrate as it has the highest enhancement factor under electrochemistry tests compared to the other two coatings.

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Zhu, Qing Jun, and Kai Wang. "Microstructure and Anti-Corrosion Properties of Arc-Sprayed Aluminum Coating in Splash Zone." Advanced Materials Research 199-200 (February 2011): 1949–53. http://dx.doi.org/10.4028/www.scientific.net/amr.199-200.1949.

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Aluminum coatings were developed by arc spray on mild carbon steel Q235. Scanning electron microscopy detection shows that the coatings have good bonding with the substrate and have low porosity. The corrosion behaviors of the coatings in splash zone were studied. The results show that free corrosion potentials of aluminum coatings are much lower than that of Q235. Potentiodynamic polarization measurements reveal that the curves of aluminum coatings have activity anodic dissolution zone, passivation zone and super-passivation zone. Corrosion morphology and energy dispersive spectrometers show that Cl- can penetrate into the coatings and some of the substrate has been corroded. The arc spray Al-coating develops a film of corrosion products on the coating surface, which tend to seal the pores in the coatings. Arc spray aluminum coatings can protect the substrate from corrosion in splash zone.

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Zhu, Ming, and Mei Shuan Li. "Thermal Stability of CrAlN Coatings." Advanced Materials Research 177 (December 2010): 249–52. http://dx.doi.org/10.4028/www.scientific.net/amr.177.249.

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Cr-Al-N coatings were deposited on the surface of the (111) single silicon for the aim to study the thermal stability of this kind of coating. The microstructure and composition of the coatings were identified by XRD and SEM/EDS, respectively. The changes of the microstructure of the coatings after being annealing in the hydrogen under 900-1100 °C were also studied by XRD analysis. The results showed that: the as-deposited coatings performed B1 microstructure with (111) preferred orientation; the microstructure of the Cr-Al-N coatings would transformed from CrN to Cr2N during the increasing of temperature and the transformation temperature increased with increasing aluminum content of the coating; AlN would also precipitate from the Cr-Al-N coating and the precipitation temperature decreased with increasing aluminum content of the coating.

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12

Drewien, C. A., R. G. Buchheit, K. R. Zavadil, and T. E. Neil. "Copper enrichment on Al 2024 surface after de-oxidizing treatment." Proceedings, annual meeting, Electron Microscopy Society of America 51 (August 1, 1993): 860–61. http://dx.doi.org/10.1017/s0424820100150137.

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Coatings of lithium-aluminum-carbonate-hydroxide are being developed for corrosion protection of aluminum alloys against atmospheric and saline environments. Coating is performed by immersion of the aluminum part into a lithium carbonate-lithium hydroxide solution of pH=11.5. Before coating, the aluminum alloy is degreased in trichloroethylene, cleaned in a sodium carbonate-sodium silicate bath, and de-oxidized in nitric acid containing ammonium biflouride. Coating of most aluminum alloys is easily accomplished, and the coatings pass the ASTM B117 salt spray test. However, aluminum alloys that contain copper, specifically 2024-T3 and 7075-T6, yield coatings that fail the salt spray test, i.e. pitting and general corrosion is observed. Photographs of coatings after 168 hr salt spray exposure are shown in Figure 1 for Al 1100 and 2024-T3 alloys. A study has been undertaken to determine the influence of copper upon the corrosion properties of the coating.The surface of 2024-T3 was analyzed after each processing step in order to determine if copper enrichment at the specimen surface was occurring.

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13

Xue, Li Li, Li Kun Xu, and Qing Fen Li. "The Influence of PtFe and Nano Aluminium Particles on the Anticorrosive Performance of Waterborne Coating." Materials Science Forum 561-565 (October 2007): 2411–14. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.2411.

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In this paper, the anticorrosive performances of fastener coatings containing PTFE and/or nano aluminum particles were investigated by using electrochemical impedance spectroscopy, scanning electron microscope. The impedance spectroscopy was interpreted by means of analysis equivalent electrical circuits. The coating capacitance of the films was monitored with the immersion time to establish the water and ions permeability of these paint films. By comparison with clear coating, PTFE and PTFE- nano aluminum pigmented coatings, the results indicated that PTFE lowers the protective properties of the waterborne epoxy film although it can provide lubricating effect. The nano aluminum powder presented the best beneficial effect and resulted in a significant increase in corrosion resistance of the PTFE- nano aluminum composite coatings. The corrosion-resistant mechanism of the effect of PTFE and nano aluminum particles in the coating is discussed.

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Jia, Rui Ling, Hong Ping Duan, Feng Guo, Xi Wei Zhai, and Ya Hong Liang. "Study on the Corrosion Resistance and Wear Resistance of Micro-Arc Oxidation Coatings on the Clad Plate of Aluminum and Magnesium Alloy." Advanced Materials Research 189-193 (February 2011): 1248–52. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.1248.

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Aluminium plate was cladded to magnesium alloy plate by using the explosive welding. The bonding morphology and composition of the explosive cladding plate was inspected by SEM and EDS. There is a wave bonding at the interface between aluminum plate and magnesium alloy plate. Then ceramic coatings were directly prepared on the surface of aluminum and magnesium alloy by micro-arc oxidation (MAO) in the same solution and at the same time. The microstructure and composition of MAO coatings were studies by SEM and EDS. The corrosion and wear resistance of MAO coatings on the two sides of the clad plate were investigated by salt spray tests and friction-wear test. The results show that the MAO coating on the Al surface consists of Al, O and Si elements, while MAO coating on the Mg surface consists of Mg, O and Si elements. The corrosion resistance of MAO coating on the Al surface was better than that on Mg surface of the explosive clad plate. The MAO coatings both on the Al surface and on the Mg surface can obviously improve the wear resistance of substrate.

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Drewien, C. A., M. O. Eatough, D. R. Tallant, C. R. Hills, and R. G. Buchheit. "Lithium-aluminum-carbonate-hydroxide hydrate coatings on aluminum alloys: Composition, structure, and processing bath chemistry." Journal of Materials Research 11, no. 6 (June 1996): 1507–13. http://dx.doi.org/10.1557/jmr.1996.0188.

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A new corrosion resistant coating, being designed for possible replacement of chromate conversion coatings on aluminum alloys, was investigated for composition, structure, and solubility using a variety of techniques. The stoichiometry of the material, prepared by immersion of 1100 Al alloy into a lithium carbonate-lithium hydroxide solution, was approximately Li2Al4CO3(OH)12 · 3H2O. Processing time was shown to be dependent upon the bath pH, and consistent coating formation required supersaturation of the coating bath with aluminum. The exact crystal structure of this hydrotalcite material, hexagonal or monoclinic, was not determined. It was shown that both the bulk material and coatings with the same nominal composition and crystal structure could be formed by precipitation from an aluminum supersatured solution of lithium carbonate.

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Lin, Ci, Surender Maddela, William G. Fahrenholtz, and Matthew J. O'Keefe. "Deposition of Cerium-Based Conversion Coatings on Aluminum Alloy 380." International Journal of Corrosion 2012 (2012): 1–9. http://dx.doi.org/10.1155/2012/760284.

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Cerium-based conversion coatings were deposited on as-cast aluminum alloy 380 substrates by a spontaneous immersion process. In this study, the effects of rinsing temperature prior to immersion in the coating deposition solution were studied with respect to the surface morphology, electrochemical response, and corrosion resistance of the coatings. Panels rinsed at25°Cprior to coating had large cracks and holes in the coating. In contrast, panels rinsed at100°Cprior to coating had a uniform coating morphology with fewer, smaller cracks. Electrochemical testing revealed that coatings deposited on substrates rinsed at100°Chad higher impedance (~80 kΩ·cm2) and lower corrosion current (~0.34 μA/cm2) compared to coatings deposited on substrates rinsed at25°C, which had 10 kΩ·cm2impedance and 2.7 μA/cm2corrosion current. Finally, ASTM B117 salt spray testing showed that rinsing at100°Cprior to coating resulted in cerium-based conversion coatings that could resist the formation of salt tails for at least 8 days.

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Oki, Makanjuola, Adesoji Adeolu Adediran, Olayinka Saheed, and Ogunsola Opeyemi. "Development and performance of hybrid coatings on aluminium alloy." Journal of Electrochemical Science and Engineering 7, no. 3 (August 15, 2017): 131. http://dx.doi.org/10.5599/jese.347.

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From gravimetric studies, hybrid nano-coatings, based on permanganate/fluoride/glycerol conversion coating solutions formed on aluminum alloy by immersion procedures developed rapidly at a rate which decreased with time of treatment and was about 16 mg in weight after a period of three minutes. The morphology of the coating during scanning electron microscopic (SEM) examinations revealed randomly shaped coating materials with mud cracking patterns, characteristics of dried out coatings derived from gel-like materials. Analyses of the coating using EDX attachment in the SEM showed that it was composed essentially of aluminum, oxygen and manganese compounds, probably hydrated. The corrosion resistance of the coating out-performed ‘bare’ aluminum alloy specimens exposed to natural environment and 1 M sodium chloride solution. The coating improved the paint adhesion characteristics of the substrate aluminum alloy.

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Dong, Xiao Feng, and Xin Mei Li. "Abrasive Wear Performance of Hot-Dipping Al-Mn Alloy Coatings on Q235." Key Engineering Materials 522 (August 2012): 13–16. http://dx.doi.org/10.4028/www.scientific.net/kem.522.13.

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The Q235 steel was modified by hot-dip-aluminizing technique, and Al-Mn alloy layer was obtained on the steel surface. Scan electron microscopy (SEM), X-ray diffraction (XRD) and abrasive wear tester were used to investigate the microstructure and wear performance of the Al-Mn alloy coatings. The results show that the surface of the obtained pure aluminum coatings is acicular, while blocks Al-Mn compounds phase exists in Al-Mn alloys layer, and the Al-Mn alloy layer is composed of Al, FeAl3, Fe2Al5 and MnAl6 phases. The experimental results showed that wear weight loss of aluminum coating is more than Q235 steel. However, after manganese added to the aluminum, Al-Mn alloy coating abrasion wear loss of weight far below the Q235 steel and aluminum coating. And weight loss increases along with Mn content decreases. When worn after 100 h, Al-13% wtMn wear alloy coating weight loss of 45% of Q235 steel, aluminum coating of 35%. So the hot-dipping Al-Mn alloy layer has excellent abrasive wear resistance.

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Shvetsov, Oleg, and Sergey Kondrat’ev. "Performance of Protective Coatings for Aluminum Alloys in the Operating Conditions of Oil Production Equipment." E3S Web of Conferences 225 (2021): 05003. http://dx.doi.org/10.1051/e3sconf/202122505003.

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The paper investigates wear resistance and corrosion resistance of protective coatings of D16 aluminum alloy under conditions that simulate operation of drill pipes. The paper also presents microstructure of coatings, electrochemical potential and corrosion rate of D16 aluminum alloy with various coatings. We evaluated adhesion and wear resistance of these coatings. D16 alloy with a tungsten carbide coating has the widest range of service properties and can be used to effectively protect the surface of aluminum drill pipes during operation operation.

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Budi, Esmar, M. Mohd Razali, and A. R. Md Nizam. "SURFACE MORPHOLOGY OF SPUTTERED TITANIUM-ALUMINUM-NITRIDE COATINGS." Spektra: Jurnal Fisika dan Aplikasinya 5, no. 1 (April 30, 2020): 79–86. http://dx.doi.org/10.21009/spektra.051.09.

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A study on the surface morphology of sputtered TiAlN coatings is presented. The coatings were deposited by DC magnetron sputtering on tungsten carbide insert tools. The surface morphology was characterized by using Atomic Force Microscopy (AFM), and the surface roughness was indicated by RMS roughness value. It was observed that the TiAlN coating surface morphology was rough as the negative substrate bias and nitrogen flow rate are increased. The evolution of the sputtered TiAlN coatings surface morphology was due to the competition between particle diffusion and re-scattering effect during the sputtering process. At high negative substrate bias and nitrogen flow rate, the re-scattering effect was prominent, leading to the high roughness of the sputtered TiAlN coating surface.

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Singh, Dalip, Veena Dhayal, and D. C. Agarwal. "Evaluate Mechanical Behavior of Alumina Coated Aluminum Alloy Using Slow Strain Rates Test in 3.5% of NaCl Solution." Materials Science Forum 969 (August 2019): 242–46. http://dx.doi.org/10.4028/www.scientific.net/msf.969.242.

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This work is concerned with the investigation of the capability of alumina coatings, deposited over aluminum alloy by dip coating methods to improve mechanical properties. Alumina coatings were deposited using oxime-modified aluminum (III) isopropoxide as a sol-gel precursor. The Scanning electron microscopy (SEM-EDX) images of the coated samples suggest deposition of uniform and crack free alumina coatings. The mechanical property of the bare, and dip coated aluminum alloy were investigated by the slow strain rate test in 3.5% of NaCl solution. The coated sample indicate higher ultimate tensile strength, it’s reflect the protective behavior of coating.

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Zhu, Sheng, Guo Feng Han, Xiao Ming Wang, Yu Xiang Liu, and Chao Ji Zhou. "Tribological Properties of TiAl Coating on Aluminum Alloy Surface by Supersonic Particles Deposition." Applied Mechanics and Materials 633-634 (September 2014): 870–73. http://dx.doi.org/10.4028/www.scientific.net/amm.633-634.870.

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In this study, Gamma TiAl intermetallic alloy protective coating was deposited on the surface of 5803 aluminum alloy by supersonic particles deposition. Researchers observed the surface morphology of the coating by SEM, and researched tribological properties of the substrate material and the coating by CETR friction and wear tester and Talysurf 5P-120 surface morphology tester. The results show that,the bonding mechanism of the Gamma TiAl intermetallic alloy coating and substrate is mechanical interlocking and metallurgical bonding. The abrasion mechanism of Gamma TiAl intermetallic alloy coating is abrasive Wear. The friction coefficients of the coating are all lower than 5083 alumium alloy. The friction volume of coatings reduced 36.7% than 5083 aluminum alloy with the friction loads 50N. TiAl coating has great function to anti-attrition and wearability.

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Malaczynski, Gerard W., Alaa A. Elmoursi, Chi H. Leung, Aboud H. Hamdi, and Albert B. Campbell. "Improved adhesion of diamondlike coatings using shallow carbon implantation." Journal of Materials Research 15, no. 3 (March 2000): 590–92. http://dx.doi.org/10.1557/jmr.2000.0088.

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A surface layer of metal carbides provides an excellent interface to achieve a highly adherent diamondlike carbon (DLC) coating. A plasma immersion ion implantation (PIII)-based procedure is described, which delivers a high retained dose of implanted carbon at the surface of aluminum alloys. A shallow implantation profile, followed by argon sputter cleaning and continued until a saturated carbon matrix is brought to the surface, provides an excellent interface for subsequent growth of DLC. At a carbon retained dose above 1018 atoms/cm2 the DLC adhesion exceeds the coating's cohesion strength. Regardless of the silicon content in the aluminum, the coating produced by this method required tensile strengths typically exceeding 140 MPa to separate an epoxy-coated stud from the coating in a standard pull test. Improved DLC adhesion was also observed on chromium and titanium. The reported tensile strength is believed to substantially exceed performance of DLC coatings produced by any other method.

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Villarreal, Iván, Miguel Aldás, Victor Hugo Guerrero-Barragan, Nelly María Rosas-Laverde, and Alexis Debut. "CaO stabilized ZrO2 coating intended to reduce corrosion on steel and aluminum substrates." Superficies y Vacío 30, no. 2 (June 15, 2017): 14–20. http://dx.doi.org/10.47566/2017_syv30_1-020014.

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In this work, we studied the anticorrosive properties of sol-gel nanostructured calcium stabilized zirconia coatings, deposited onto 304 stainless steel and commercial aluminum substrates by dip-coating and spin-coating. During the ceramic oxide synthesis, zirconium oxychloride octahydrate was used as precursor and calcium acetate monohydrate was used as stabilizer of the cubic zirconia structure, in a precursor/stabilizer molar ratio of 0.84/0.16. The gel films deposited on steel and aluminum were heat treated at 550 y 600 °C during 5 and 10 min, respectively, and the adherence of the resulting ceramic films was evaluated. Continuous coatings were obtained that reached average thicknesses between 2 y 3 mm when deposited on stainless steel, and between 1.5 y 1.6 on aluminum, depending on the coating method. The corrosion resistance of the best-adhered coatings was evaluated during 500 h in a saline chamber, according to ASTM B117-11. All the substrate-coating combinations showed a very good corrosion resistance. For the two substrate types, the films deposited by dip-coating showed higher corrosion resistance than the ones deposited by spin-coating. The anticorrosive protective effect of the coatings was better for the aluminum substrates, compared to the stainless-steel substrates.

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Vodennikov, S. A., V. O. Skachkov, and O. S. Vodennikova. "Protective and strengthening coatings on reinforcing steels." Metaloznavstvo ta obrobka metalìv 96, no. 4 (December 1, 2020): 39–46. http://dx.doi.org/10.15407/mom2020.04.039.

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A conceptually new technology for the application of aluminum coatings on 18G2C steel by the electrolytically deposited NaF-NaCl - AlF3 ionic melt method has been developed. To solve the tasks set in the work, a set of experimental and computational research methods was used: metallographic analysis, energy dispersion microanalysis, mechanical tests, and calculation of the oxidation rate of samples. The mechanical characteristics of the samples of reinforcing steel were determined on a rupture machine FP-100 at an active capture rate of 2.5 mm / min. The relationship between the rates of electrochemical oxidation of the aluminide coating, its mechanical properties, with the distribution of aluminum in the depth of the samples and its phase composition have been determined. The increase of mechanical characteristics of samples from 18G2S steel with an aluminum covering in comparison with usual reinforcing steel is shown. The sequence of structural-phase changes of metal in the process of aluminide coating is determined and its influence on mechanical and corrosion resistance is determined. Experimental evaluation of the rate of oxidation of 18G2C steel samples with aluminum coating under the conditions of sulfuric acid electrolyte at an electric current of 11 to 18 A has been conducted. The developed technology of electrolytic deposition of aluminum has scientific and practical interest for the construction industry. The developed coating makes it possible to increase the mechanical properties of steel by almost 12% and to increase the corrosion resistance. Keywords: aluminum coatings, 18G2C steel, electrochemical oxidation, electrolytic deposition.

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Lindner, Martina. "Effect of Substrate Strain, Aluminum Thickness and Corona Pretreatment on the Electrical Resistance of Physical Vapor Deposited Aluminum Coatings." Coatings 10, no. 12 (December 17, 2020): 1245. http://dx.doi.org/10.3390/coatings10121245.

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Aluminum coatings applied to polymer films by physical vapor deposition should be defect-free for applications such as packaging and electronic devices. However, cracks can appear in the aluminum coating as the polymer film stretches, becoming manifest as an increase in resistance. We evaluated the effect of different aluminum thicknesses (10–85 nm), polymer films (polyethylene terephthalate or polypropylene), and corona doses (0–280 W∙min/m2) on the relative increase in resistance during stretching (strain = 0–100%). We found that the thickness of the aluminum coating was inversely related to the increase in resistance. Corona pretreatment led to an increase in surface energy (≤40 mN/m for polypropylene; ≤50 mN/m for polyethylene terephthalate) although high corona doses resulted in overtreatment, which limited the adhesion of aluminum to the substrate and led to a greater increase in resistance. Varying the coating thickness had a much greater effect than the corona pretreatment, suggesting that thicker aluminum coatings are more effective than corona pretreatment as a strategy to increase coating stability. The effect of aluminum thickness and strain on resistance was described using a fit function containing three fit factors.

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He, Long, Ye Fa Tan, Bin Cai, Hua Tan, Li Gao, and Zhong Wei Zhang. "Research on Friction and Wear Properties of Plasma Spraying Ni-Base Alloy Coatings on Aluminum Alloy Surfaces." Advanced Materials Research 538-541 (June 2012): 207–13. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.207.

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In order to improve the wear resistance and extend service life of aluminum alloy parts, the Ni-base alloy anti-wear coatings were prepared on the surfaces of 7A05 aluminum alloy by plasma spraying technology. The microstructure and interface of the coatings were analyzed, and the friction and wear properties of Ni-base alloy coatings and aluminum alloy substrates were investigated under dry friction condition at room temperature. The research results show that the main phases of Ni-base alloy coating are γ-Ni, CrB and Cr23C6. The thicknesses of diffusion layers existing between intermediate layer and coating, intermediate layer and substrate are respectively 15μm and 20μm. The bonding types of the coating and the substrate are mechanical combination accompanied with partially metallurgical combination. When wore against GCr15 steel balls, the average friction coefficient of the Ni-base alloy coatings is 11.6% lower than that of the aluminum alloy substrates, and the average wear loss of the former is 9.3mg, which is only 1/3 of that of the latter. With the increase of loads, the wear mechanisms of the Ni-base alloy coatings change from slightly micro-cutting wear and fatigue wear to abrasive wear and micro-fracture wear, while those of the aluminum alloy substrates are mainly adhesive wear and abrasive wear as well as slight oxidation wear.

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Petrova, Larisa, Victor Alexandrov, and Maxim Morshchilov. "Factors of quality increase in protective chromium coatings on aluminum alloys obtained through pyrolytic precipitation." Science intensive technologies in mechanical engineering 2020, no. 10 (October 30, 2020): 3–9. http://dx.doi.org/10.30987/2223-4608-2020-10-3-9.

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There are considered the problems of control parameter detection in the process of pyrolytic chromium coatings on aluminum alloy and the investigation of their impact upon coating structure, strengthening indices, adhesion strength, and also upon kinetics of coating growth. The investigations have shown that the method mentioned is promising for aluminum alloy surface strengthening, and also it allows obtaining chromium coatings with high hardness and thick constant possessing increased wear-resistance.

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Zhang, Li Gong, Gui Mei Zhao, and Xiao Ming Lai. "Anti-Wear Coating Grown by Micro-Plasma Oxidation on Aluminum Alloys in the Solution of Aluminate-Titania." Advanced Materials Research 239-242 (May 2011): 667–70. http://dx.doi.org/10.4028/www.scientific.net/amr.239-242.667.

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In this paper, Aluminum trioxide ceramic coatings were grown on surfaces of 2024 Aluminum alloys by micro-plasma oxidation in an aluminate electrolytic solution. In order to decrease the density of the pores and increase the anti-wear property of the ceramic coatings, Titania were added into the aluminate electrolytic solution. The struture and anti-wear property of the produced ceramic coatings were measured by X-ray diffraction, scanning electron microscope , hardness tester and frictionometer. The results show that the thickness of the ceramic coating is about 24±1 μm, surfaces of the ceramic coatings are very uniform. The hardness of the doped coating is up to 930 HV, and the wear property of the coating is the more excellent than that of undoped coating.

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Wang, Zhao Jun, Guang Ming Zhu, and Feng Shi Yin. "Study on the Microstructure of FeCrAl/Aluminum Bronze Composite Coatings Prepared by Supersonic Electric Arc-Spraying." Applied Mechanics and Materials 217-219 (November 2012): 1346–49. http://dx.doi.org/10.4028/www.scientific.net/amm.217-219.1346.

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Abstract. FeCrAl/aluminum bronze composite coatings were prepared by supersonic electric arc-spraying. The microstructure of the composite coating was studied by using optical microscope (OM), scanning electron microscope (SEM). The results show that the FeCrAl and QAl7 aluminum bronze composite coatings have a typical layered structure which is composed of FeCrAl, QAl7 aluminum bronze flattened particles as well as alumina films between them. FeCrAl and QAl7 aluminum bronze flattened particles are distributed alternately and have a good combination btween each other.

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Wen, Yu Qing, Hui Min Meng, Wei Shang, and Xiu Juan Jiang. "Electrochemical Characteristics of the Rare Earth Compound Coating on 6061 Aluminum Alloy." Applied Mechanics and Materials 71-78 (July 2011): 2361–65. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.2361.

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The composite coatings were prepared on aluminum alloy by anodizing and chemical conversion method. The coatings consisted of a anodic oxide coating and a rare earth conversion coating. The surface morphology and composition of the composite coatings were analyzed by scanning electron microscopy (SEM) and energy dispersive X-rays (EDX). The electrochemical properties of the different samples were researched by Potentiodynamic polarisation and electrochemical impedance spectroscopy in a 3.5-wt.% NaCl solution. The results showed that corrosion current density of the sample with composite coatings was 3.611×10-9 A·cm-2, impedance was 6.107×105 Ω·cm-2. The composite coatings had better corrosion resistance than the sample with anodic oxide film and the aluminum alloy substrate.

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Quadrini, Fabrizio, Denise Bellisario, Carmine Lucignano, and Loredana Santo. "Epoxy-Matrix MMT-Filled Nanocomposite Coatings onto Aluminum Substrates." International Journal of Surface Engineering and Interdisciplinary Materials Science 2, no. 1 (January 2014): 1–14. http://dx.doi.org/10.4018/ijseims.2014010101.

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Epoxy base nanocomposite coatings were prepared by using organomodified montmorillonite (MMT) as filler and aluminum as substrate. A fast fabrication procedure was utilized so as to investigate the feasibility of industrial processes. After optimization of the coating process conditions, MMT filled coatings were produced by changing the MMT content and the mixing time. Many tests were performed to evaluate the coating performances: scratch and wear test, surface and gloss analysis. The effect of the MMT content on the coating properties is noticeable but not always ameliorative. On the other hand, it is questionable if the direct strengthening effect of the MMT particles is stronger than the indirect effect of the filler on the coating thickness. Anyway, best performances were measured in the case of low MMT content even if data scattering can be high.

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Wu, Yan Bo, Si Si Zeng, and Peng Sun. "Comparison of Two Different Chemical Conversion Coating on Aluminum Alloy." Advanced Materials Research 146-147 (October 2010): 208–11. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.208.

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In this paper, we made two different chemical conversion coatings on aluminum alloy by TiOSO4 and Na2WO4. The morphology of the chemical conversion surface layers were observed by scanning electron microscopy (SEM). The microcosmic phase structures were characterized using X-ray diffraction (XRD). Electrochemical method was used to study the coatings corrosion resistance. The results indicated that the two conversion coatings were crystal structure material, the surface of coating were both show pothole structure. TiOSO4 coating have better corrosion resistance than Na2WO4 coating.

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Rudnik, Ewa, Tomasz Jucha, Lidia Burzynska, and Krzysztof Ćwięka. "Electro- and Electroless Deposition of Ni/SiC and Co/SiC Composite Coatings on Aluminum." Materials Science Forum 690 (June 2011): 377–80. http://dx.doi.org/10.4028/www.scientific.net/msf.690.377.

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Aluminum and its alloys characterize usually poor superficial properties. To improve hardness and wear resistance, aluminum base materials are covered by protective layers. Deposition of metallic coatings on aluminum is accompanied by some difficulties due to tenacious oxide layer present on the substrate surface. Hence, some additional stages are needed to assure good adhesion of the coating to the substrate. In many cases, electrodeposition and electroless methods are competitive for providing deposits with ceramic particles uniformly incorporated within the metal layer. The most extensive studies were carried out on deposition of Ni/SiC composites, but no attempts on Co/SiC coatings deposition on aluminum have been performed. Experiments presented were conducted to develop simply methods for deposition of Ni/SiC and Co/SiC composite coatings on aluminum substrate. The consecutive stages of the hydrometallurgical route were: zincating of aluminum in alkaline solutions, electroless nickel (cobalt) deposition and electrodeposition or electroless deposition of the composite coating. The influence of deposition time and composition of the baths on thickness and composition of the deposits was studied. Microstructure and microhardness of as-plated individual layers were also determined.

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Zhao, Kun, Wan Chang Sun, Chun Yu Miao, Hui Cai, Ju Mei Zhang, and Li Bin Niu. "Microstructure and High-Temperature Oxidation of Ni-Si₃N₄ Composite Coatings by Pulse Electrodeposition." Materials Science Forum 817 (April 2015): 421–25. http://dx.doi.org/10.4028/www.scientific.net/msf.817.421.

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Nickel matrix and Si3N4 micron particles were co-deposited on the aluminum alloy by pulse electro-deposition for high temperature performance. Meanwhile, the oxidation resistance was evaluated through the high temperature oxidation test. The phase structure, micrographs and components of the composite coatings were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) together with energy dispersive spectroscopy (EDS) respectively. The results indicated that Si3N4 particles were uniformly distributed across the coating and there were no pores and cracks or other defects at the coating/substrate interface. Ni-Si3N4 composite coatings are characterized by pyramidal micro-crystallite structure. The thickness of Ni-Si3N4 composite coatings were up to 80 μm for 2h. The results also revealed that the Ni-Si3N4 composite coatings presented better oxidation resistance than the pure Ni coating and aluminum alloy at high temperature. After oxidation at 673 K for 8h, the oxidation resistance of Ni-Si3N4 composite coatings presented the improved oxidation resistance behavior compared to pure Ni and the aluminum alloy, respectively.

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LEI, BING, GUOZHE MENG, and WEI LIU. "SYNTHESIS OF ORGANIC–INORGANIC HYBRID COATINGS FOR THE PROTECTION OF ALUMINUM SUBSTRATES." Surface Review and Letters 28, no. 05 (March 4, 2021): 2150033. http://dx.doi.org/10.1142/s0218625x21500335.

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A silica-based organic–inorganic hybrid coating has been developed for corrosion protection of aluminum substrates by dip-coating technique. The hybrid sols were prepared by hydrolysis and condensation of trimethoxy(7-octen-1-yl)silane (TMOS) and tetraethyl orthosilicate (TEOS) in the presence of acetic acid. Structural characterization of the hybrid coatings was performed using powder X-ray diffraction analysis (PXRD). The morphology of the coating has been studied by scanning electron microscope (SEM). Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) tests have been performed, and the results showed that the silane coatings had high corrosion resistance. The heat treatment of the coatings at various temperatures have been investigated, and the results show that 130∘C is an optimized temperature. The results expose that the hybrid coating enhanced the corrosion protection of aluminum in aqueous 3.5% NaCl solution.

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Gao, Yuhang, Xiaohong Chen, Ping Liu, Honglei Zhou, Shaoli Fu, Wei Li, Xinkuan Liu, Fengcang Ma, Yanbo Zhu, and Jiayan Wu. "Influence of high-temperature aluminizing treatment on the corrosion resistance of 90/10 copper-nickel alloy." Anti-Corrosion Methods and Materials 68, no. 5 (August 20, 2021): 365–72. http://dx.doi.org/10.1108/acmm-04-2021-2467.

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Purpose This study aims to investigate the effect of coatings prepared by the addition of copper-aluminum alloy powder on the corrosion behavior of 90/10 copper-nickel alloy. Design/methodology/approach Coatings of copper-aluminum alloy powder at different contents (Wt.% = 50%, 60%, 70% and 80%) were prepared by the high-temperature heat treatment process. The microstructure and component of the coatings were characterized by scanning electron microscope, X-ray diffraction, energy dispersive spectrometer and X-ray photoelectron spectroscopy. The electrochemical properties of the coating were explored by electrochemical impedance spectroscopy. Findings The results show that the aluminized layer was successfully constructed on the surface of 90/10 copper-nickel alloy, the composition of the coating was composed of copper-aluminum phase and aluminum-nickel phase, the existence of the aluminum-nickel phase was formed by the diffusion of Ni elements within the substrate and because of the diffusion, the Al-Ni phase was distributed in the middle and bottom of the coating more. The Al-Ni phase is considered to be the enhanced phase for corrosion resistance. When the copper-aluminum alloy powder content is 70 Wt.%, the corrosion resistance is the best. Originality/value The enhancement of corrosion resistance of 90/10 copper-nickel alloy by the copper-aluminum alloy powder was revealed, the composition of the aluminized layer and the mechanism of corrosion resistance were discussed.

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Yao, Wen Li, Qian Li, Mou Cheng Li, Jie Yu Zhang, and Kuo Chih Chou. "High Anticorrosive Properties of Hot-Dip 55 wt% Al-Zn-Si Coatings on Q235 Steel." Advanced Materials Research 146-147 (October 2010): 306–9. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.306.

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A comparative study of the morphology and anticorrosive behaviour of commercial 55 wt% Al-Zn-Si coatings (CC) and hot-dip 55 wt% Al-Zn-Si coatings (HD) on Q235 steel was performed by using surface analysis techniques and electrochemical measurements. Despite the ingredients of the Al-rich dendritic phase for HD coating similar to the ingredients for CC coating, aluminum content in the Zn-rich phase for HD coating was almost twice higher than aluminum content for CC coating. The difference of surface morphologies and chemical compositions in Zn-rich phases for the two 55 wt% Al-Zn-Si coatings could significantly affect their corrosion properties. The corrosion behavior of the two coatings was investigated in 0.01 mol L-1 NaCl + 0.01 mol L-1 NaHSO3 aqueous solution. Both polarization curve and electrochemical impedance spectroscopy results indicate HD coatings had much higher corrosion resistance than CC ones.

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Xu, Yiku, Shuang Ma, Mingyuan Fan, Hongbang Zheng, Yongnan Chen, Xuding Song, and Jianmin Hao. "Mechanical and Corrosion Resistance Enhancement of Closed-Cell Aluminum Foams through Nano-Electrodeposited Composite Coatings." Materials 12, no. 19 (September 29, 2019): 3197. http://dx.doi.org/10.3390/ma12193197.

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This work aims to improve the properties of aluminum foams including the mechanical properties and corrosion resistance by electrodepositing a SiC/TiN nanoparticles reinforced Ni–Mo coating on the substrate. The coatings were electrodeposited at different voltages, and the morphologies of the coating were detected by SEM (scanning electron microscope) to determine the most suitable voltage. We used XRD (x-ray diffraction) and TEM (transmission electron microscope) to analyze the structure of the coatings. The aluminum foams and the substrates on which the coatings were electrodeposited at a voltage of 6.0 V for different electrodeposition times were compressed on an MTS (an Electro-mechanical Universal Testing Machine) to detect the mechanical properties. The corrosion resistance before and after the electrodeposition experiment was also examined. The results showed that the coating effectively improved the mechanical properties. When the electrodeposition time was changed from 10 min to 40 min, the Wv of the aluminum foams increased from 0.852 J to 2.520 J and the σs increased from 1.06 MPa to 2.99 MPa. The corrosion resistance of the aluminum foams was significantly improved after being coated with the Ni–Mo–SiC–TiN nanocomposite coating. The self-corrosion potential, pitting potential, and potential for primary passivation were positively shifted by 294 mV, 99 mV, and 301 mV, respectively. The effect of nanoparticles on the corrosion resistance of the coatings is significant.

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Yan, Xiaoxing, Lin Wang, and Xingyu Qian. "Preparation and Characterization of Low Infrared Emissive Aluminum/Waterborne Acrylic Coatings." Coatings 10, no. 1 (January 1, 2020): 35. http://dx.doi.org/10.3390/coatings10010035.

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An aluminum/waterborne acrylic coating was developed by orthogonal experiments, and the gloss, emissivity, chromatic distortion, hardness, adhesion, impact resistance, and corrosion resistance of the coatings were examined. The results showed that the effect of drying time on the infrared emissivity of coatings was more significant than that of the Al powder concentration and nano-silica slurry. When the drying time was prolonged from 0.5 to 6.0 min, the gloss of the coating decreased slowly and the gloss remained low. The infrared emissivity first decreased and then increased. The infrared emissivity of coatings dried for 2.0 min was better. The L’ value gradually decreased and showed a small change of range. With the increasing of the drying time, the hardness of the coating gradually decreased and was the highest at 0.5–2.0 min. The drying time had no effect on the adhesion level. The impact resistance of the coating was better during the drying period of 1.0–3.0 min. The corrosion resistance of the coating was better at 2.0 min. When the drying time was 2.0 min, the waterborne coating showed the better comprehensive performance. This study provides new prospects in using low infrared emissive coatings for infrared stealth and compatibility with visible light.

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Gusev, V. M., O. Yu Elagina, and A. G. Buklakov. "Improving the properties of plasma heat-resistant coatings by means of spraying materials that reacting with exothermic effects." Physics and Chemistry of Materials Treatment 2 (2021): 51–55. http://dx.doi.org/10.30791/0015-3214-2021-2-51-55.

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The quality of heat-resistant coatings deposited by flame spraying is largely determined by the adhesion of the coating to the surface of the part. One of the ways to increase adhesion is to deposition intermediate layers of thermosetting powders between the base material and the coating. In this work, two versions of heat-protective coatings are investigated — a two-layer coating consisting of an Al – Ni sublayer (20 – 80 wt. %) and a main ZrO2 layer, and a single-layer coating sprayed from an aluminum-clad zirconium oxide powder (20 ZrO2 – 80 Al, wt. % ). The method of differential thermal analysis was used to determine the temperature ranges and values of the exothermic effects of oxidation and redox reactions during heating of Al – Ni and ZrO2 clad powders. A significant exothermic effect was found during oxidation of the aluminum cladding shell in the temperature range of 360 °C and a stronger thermal effect due to the redox reaction at a temperature of 920 °C. The microstructure and microhardness of the obtained coatings have been studied, and their thermal conductivity and adhesion have been assessed. The resistance of the coatings during thermal cycling tests has been determined. It has been established that thermal protective coatings made of aluminum-clad zirconium oxide powder have the best characteristics under thermal cycling conditions. A higher level of adhesion and thermal cyclic resistance of such coatings are due to an increase in the enthalpy of aluminum-clad ZrO2 powders due to exothermic reactions and the presence of a metal binder.

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Sang, Ke Zheng, Rui An, Zhi Wen Huang, Hong Wei Li, and Jun-Ichi Matsushita. "Effect of Silica on the Wettability and Composition of the Alumina/Aluminum Interface." Materials Science Forum 868 (August 2016): 68–72. http://dx.doi.org/10.4028/www.scientific.net/msf.868.68.

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In order to improve the wetting ability of metal to ceramic, silica coatings on alumina/ mullite ceramics were prepared with tetraethyl orthosilicate (TEOS) by sol-gel method. The preparation processing was optimized. Furthermore, the interactions between the aluminum melt and the ceramic with or without silica coating were investigated. The results showed that the silica coatings could be successfully prepared. The molten aluminum melt reacted with silica, and alumina was formed at the interface between ceramic and metal. The ceramic (alumina/ mullite) substrates could be infiltrated by aluminum melts due to the existence of mullite. The silica coatings conduced to the infiltration and improved the combination between the ceramic and aluminum at the interface.

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Vaidya, K. J., and L. F. Francis. "Processing of calcium metaphosphate-based glass-ceramic coatings on alumina." Journal of Materials Research 11, no. 1 (January 1996): 100–109. http://dx.doi.org/10.1557/jmr.1996.0013.

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Dense, crystalline, glass-ceramic coatings containing calcium metaphosphate and aluminum phosphate were prepared on aluminum oxide substrates by a three-step method. The processing involved glass (40 mol% CaO, 10 mol% Al2O3, 50 mol% P2O5) formation, deposition of a glass particle coating, and heat treatment to sinter the glass and crystallize the phosphates. Sintering and microstructure evolution were influenced by wet coating thickness, heat-treatment temperature, time, and heating rate. Heat treatment for 1 h at 725 °C using a 50 °C/min heating rate was found to give a dense, crack-free coating. The resultant coating microstructure has spherulitic morphology (0.3 μm size) with aluminum phosphate in the center of the spherulite. The hardness of the fully crystallized glass-ceramic coating was ∼5.2 GPa.

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Jiang, Qiong, Qiang Miao, Wen Ping Liang, Bei Lei Ren, Yi Xu, and Zheng Jun Yao. "Characterization of Microstructure, Phase Composition and Corrosion Resistance of Al-Zn-Si-RE Waterborne Coatings." Advanced Materials Research 887-888 (February 2014): 1076–79. http://dx.doi.org/10.4028/www.scientific.net/amr.887-888.1076.

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New waterborne Al-Zn-Si-RE coatings with improved corrosion resistance were introduced in this study. The corrosion resistance of Al-Zn-Si-RE coatings was evaluated by electrochemical measurements and salt spray test. Evolution of microstructure and phase composition at different exposure time in salt spray test was investigated by scanning electron microscopy and X-ray diffraction technique. The results indicate that Al-Zn-Si-RE coatings provide effective sacrificial protection to the steel substrate but exhibit lower corrosion rate and higher corrosion resistance compared to zinc aluminum coatings. The dense continuous corrosion layer formed on Al-Zn-Si-RE coating acts as a barrier layer, limiting the transport of aggressive species towards the coating-substrate interface and the corrosion rate of the coating; Zinc aluminum hydroxy carbonates are the dominant components in the corrosion layer of Al-Zn-Si-RE coatings.

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Liu, Ming, Zhi Hua Sun, Zhi Shen Wang, Xiao Yun Zhang, and Feng Lu. "Insulation Treatment of 2A12 Aluminum Alloy Surface by Plasma Electrochemical Oxidation." Materials Science Forum 687 (June 2011): 297–302. http://dx.doi.org/10.4028/www.scientific.net/msf.687.297.

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The 2A12 aluminum alloy surface is treated by plasma electrochemical oxidation (PEO) in alkaline solution. X-ray Diffraction (XRD) is used to analyze the phases of PEO coatings. Scanning Electron Micrograph (SEM) is used to investigate the compactness of PEO coatings. High resistance meter and voltage resistance meter are used to measured Electric resistance and breakdown field strength of PEO coatings respectively. The results show that the PEO coating is composed of α-Al2O3, γ-Al2O3 , etc, and they are all well-insulated substance which is profitable to insulation of 2A12 aluminum alloy. When the thickness of PEO is more than 60μm, porosity in the PEO coating is estimated not more than 15%. Electric resistivity of PEO coatings can reach as high as 1013 Ω·cm, and breakdown field strength of the PEO coatings can reach 72 V / μm.

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Liu, Wanying, Junjie Yang, Yuhong Qiu, Ying Liu, and Kuanhai Deng. "Titanium carbide’s effects on coatings formed on D16T aluminum alloy by plasma electrolytic oxidation." Anti-Corrosion Methods and Materials 67, no. 1 (January 6, 2020): 48–58. http://dx.doi.org/10.1108/acmm-06-2019-2149.

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Purpose The preferable concentration of titanium carbide was optimized and added as an additive to the micro-arc oxidation electrolyte to produce a high corrosion-resistant coating on D16T aluminum alloy. Design/methodology/approach Ceramic coatings were deposited on D16T aluminum alloy by plasma electrolytic oxidation in alkaline silicate electrolytes with micron titanium carbide particle suspending at different concentrations. Influences of additive concentration on morphology, elemental and phase composition and corrosion resistance of doped PEO coatings were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and electrochemical methods, respectively. Findings Results revealed that suspending titanium carbide additives incorporated into ceramic coatings through discharging channels and chemically transformed into amorphous stage. The content of titanium in the doped coatings increased with the increasing concentration of suspending micron additive. Compared with the coating without particle addition, the corrosion resistance of the coating produced in 8 g/L titanium carbide suspension increased more than 20 times. The result indicated that the incorporation of titanium into the PEO coatings formed on the D16T aluminum alloy could effectively improve the corrosion resistance. Originality/value The mechanism of corporation of TiC and the mechanism of improving the corrosion resistance of the coating were proposed.

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Ezirmik, Kadri Vefa. "Corrosion and High Temperature Oxidation Behavior of Structural Steels Coated with Aluminum Alloys." BEN Vol:2 Issue:3 2021 2, no. 3 (April 2, 2021): 22–26. http://dx.doi.org/10.36937/ben.2021.003.005.

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Structural steels are among the most widely used materials in today's industry. Various surface coating processes are used to protect structural steels from corrosion in atmospheric or aggressive environments. The most commonly used method is the galvanizing process based on forming zinc coating on the steel surface by using the hot dip method. Zinc coatings are insufficient to protect against corrosion, especially in chlorinated environments. Aluminum and its alloys stand out as an alternative material group to zinc in chlorinated environments. In this study, aluminum and aluminum alloy coatings, which are thought to be an alternative to zinc coating, were coated on the structural steel surface using the hot dip method. To examine how different aluminum alloys affect the corrosion and high-temperature oxidation properties of steels, nearly pure AA1050, high Cu content AA2024, and high Mg content AA5083 alloys were coated on structural steels. The coating process was carried out by dipping the structural steels into molten aluminum baths kept at a constant temperature of 700°C for 1, 3, and 5 minutes. The optimum adhesion and surface properties were obtained from dipping time for 3 minutes. The properties of coatings and intermetallic structures formed at the coating-steel interface were examined using an optical microscope, X-ray Diffractometer (XRD), Scanning Electron Microscope (SEM), and Energy Scattering Spectroscopy (EDS) systems. To examine the high-temperature oxidation properties of the coatings, the coated samples were oxidized for 24 hours at 750°C under open-air conditions, and the changes in weight were investigated. Immersion corrosion tests were performed in 3.5% NaCl solution, and corrosion losses and degradation patterns were investigated. As a result of the studies, it has been determined that the Al coatings produced by the hot dip process significantly increase the oxidation and corrosion resistance of the structural steels.

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Dudareva, N. Yu, and R. F. Gallyamova. "The Effect of Silicon in Al-Si Alloys and Electrical Treatment Modes on Structure and Properties of MAO-Coatings." Solid State Phenomena 299 (January 2020): 737–42. http://dx.doi.org/10.4028/www.scientific.net/ssp.299.737.

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The work shows the influence of the content of silicon in the aluminum alloy and the regimes of micro-arc oxidation (MAO) on the structure and properties of the formed coatings. Treatment of samples from high-silicon aluminum alloys AK12pch (Si ~12 %) and M244 (Si ~25 %) was carried out in two modes, which have different installation capacity MAO. The thickness, micro-hardness, porosity of the formed MAO coatings was investigated. It is established that the increase in the proportion of silicon in the aluminum alloy leads to the formation of MAO coatings of significant thickness (~230 μm), with low micro-hardness (HV ~650) and high porosity (up to ~16 %). Increase 4 times the installation capacity of MAO causes the growth of the thickness of the coating, reduces the porosity of the coating on the alloy AK12pch and increases the porosity of the coating on the alloy M244.

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Cheruvu, N. S., K. S. Chan, and G. R. Leverant. "Cyclic Oxidation Behavior of Aluminide, Platinum Modified Aluminide, and MCrAlY Coatings on GTD-111." Journal of Engineering for Gas Turbines and Power 122, no. 1 (October 20, 1999): 50–54. http://dx.doi.org/10.1115/1.483174.

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Cyclic oxidation behavior of aluminide, platinum modified aluminide, and MCrAlY coatings has been investigated at three temperatures. Aluminide and platinum modified coatings were deposited on GTD 111 material using an outward diffusion process. CoCrAlY coating was applied on GTD-111 by Electron Beam Physical Vapor Deposition (EB-PVD). The oxidation behavior of these coatings is characterized by weight change measurements and by the variation of β phase present in the coating. The platinum modified aluminide coating exhibited the highest resistance to oxide scale spallation (weight loss) during cyclic oxidation testing. Metallographic techniques were used to determine the amount of β phase and the aluminum content in a coating as a function of cycles. Cyclic oxidation life of these coatings is discussed in terms of the residual β and aluminum content present in the coating after exposure. These results have been used to calibrate and validate a coating life model (COATLIFE) developed at the Material Center for Combustion Turbines (MCCT). [S0742-4795(00)00801-2]

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Wang, Bing Ying, and Zhen Tong Sun. "Corrosion Behavior of High-Strength Pipeline Steel and Coatings in the Simulated Sea Water Environment." Materials Science Forum 686 (June 2011): 533–38. http://dx.doi.org/10.4028/www.scientific.net/msf.686.533.

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Four different metal coatings of pure aluminum, aluminum zinc alloy, titanium, aluminum Titanium were prepared on the surface of X80 pipeline steel by the method of arc spraying.The microstructures and combination method between the four coatings and substrates were observed by means of metallurgical microscope.This paper use 3.5%(mass fraction) NaCl solution to simulate seawater. The corrosion potential, average corrosion rate and corrosion current density of the four metal coatings were studied through the immersion test, salt spray test and electrochemical experiment in 3.5% NaCl solution.According to the results,analyse the corrosion mechanism of different coatings compared to the different corrosion resistances. The results showed that the Al-Zn coating has the excellent comprehensive corrosion resistance.

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Journal articles on the topic 'Aluminum coatings'

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