The cracking behaviors of anodic films on 1050 and 2024 aluminum alloys after heating up to 300°C

Xin, Zhao; Liu, Weihua; Zuo, Yu; Yang, Lizhong

doi:10.1016/j.jallcom.2008.12.101

Cited by 11 publications

(4 citation statements)

References 30 publications

(37 reference statements)

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“…The surface has a sintering feature [ Fig. 20,21 The XRD result shown in Fig. There are a number of micropores and crater structures distributed on the surface of the blue ceramic coating.…”

Section: Resultsmentioning

confidence: 99%

In situ fabrication of blue ceramic coatings on wrought Al Alloy 2024 by plasma electrolytic oxidation

Wang

Nie

et al. 2012

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Articles you may be interested inEffect of current density on the microstructure and corrosion resistance of microarc oxidized ZK60 magnesium alloy Biointerphases 9, 031009 (2014); 10.1116/1.4889734 Effect of CeO 2 addition on the properties of FeAl based alloy produced by mechanical alloying technique AIP Conf. Proc. 1555, 7 (2013); 10.1063/1.4820980 Microstructural analysis and oxidation protection behavior of Cr-Ni surface coatings of 347 stainless steel by rapid mirror scanning of a high power C O 2 laserIn situ formation of ceramic coatings on 2024 Al alloy with a blue color was successfully achieved using a plasma electrolytic oxidation process working at atmospheric pressure. This novel blue ceramic coating overcomes the shortcomings of surface treatments resulting from conventional dyeing processes by depositing organic dyes into the porous structure of anodic film, which has poor resistance to abrasion and rapid fading when exposed to sunlight. X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy were employed to characterize the microstructure of the blue ceramic coating. The fabricated ceramic coating was composed of CoAl 2 O 4 , a-Al 2 O 3 , and c-Al 2 O 3. By controlling the working parameters, the distribution of the CoAl 2 O 4 phase on the surface can be adjusted, and plays a key role in the appearance of the coating. Electrochemical testing, thermal cycling method, and pin-on-disk sliding wear testing were employed to evaluate corrosion, thermal cycling, and wear resistance of the ceramic coatings.The results indicate that the blue ceramic coating has a similar polarization resistance to that of conventional anodic film and can significantly enhance the corrosion resistance of aluminum alloy. There are no destructive horizontal cracks observed within the blue ceramic coating when subjected to 120 times of thermal cycling, which heats the samples up to 573 K and followed by submersion in water at room temperature for 10 min. Compared with the aluminum substrate as well as a conventional anodic film coated aluminum sample, the wear resistance of the blue ceramic coating coated sample was significantly increased while the coefficient of friction was decreased from 0.34 to 0.14.

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Section: Resultsmentioning

confidence: 99%

In situ fabrication of blue ceramic coatings on wrought Al Alloy 2024 by plasma electrolytic oxidation

Wang

Nie

et al. 2012

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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“…The ions promote the formation of oxygen bubbles, disrupting the growth of the coating, causing a disordered pore morphology and a rough surface with cavity defects. [52][53][54][55] The irregularity of the porous structures and the cavities do not only appear on the surface of the coating but are also clearly visible in the cross-section STEM images. The images further show a clear distinction between the alloy substrate and the anodic coating.…”

Section: Anodizationmentioning

confidence: 98%

Sustainable Surface Functionalization of Lightweight Materials : Cerium Oxide Nanoparticles Replacing Chromium in Anodic Coatings and Carbon Nanomaterials for Lightning Strike Protection

Poot

2022

Linköping Studies in Science and Technology. Licentiate Thesis

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Aviation accounts for 2-3% of the carbon dioxide emitted globally. One way to reduce emissions is to develop and introduce sustainable, functional, lightweight materials and coatings that increase the lifetime and fuel efficiency of aircraft. The main lightweight materials used in the aerospace industry today are aluminum alloys and carbon fiber reinforced plastic composites. In the work presented in this licentiate thesis, a new sustainable alternative for the replacement of toxic hexavalent chromium in a low energy and chemical consumption sealing procedure of anodized aluminum alloys is suggested (paper I and II). An alternative to the conventional metal mesh used as lightning strike protection for composite structures used today is also presented. The proposed solution adds considerably less weight and has a possibility to reduce the CO2 emission from aviation (paper III).Aluminum alloys as well as composites both exhibit high strength-to-weight ratios but come with individual drawbacks. Fiber reinforced plastics exhibit limited electrical conductivity, which is why additional protection is needed to avoid severe damage following a lightning strike. Aluminum alloys have instead the disadvantage of being susceptible to corrosion and surface protection is required to prolong the materials lifetime and to avoid devastating failures. Anodization, formation of a porous aluminum oxide coating, is the most common choice of surface treatment. This is often followed by closure of the pores through a sealing procedure. Both processes have up until recently been performed in large, energy consuming tanks with highly toxic solutions containing hexavalent chromium which must be replaced to reduce the environmental impact.Author contribution: Poot was involved in the planning of the project and responsible for anodization, sealing by immersion, SEM and STEM characterizations, and corrosion testing. Poot is the main author of the manuscript.

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“…The differential thermal dilatations between the substrate and the film can lead to the crazing of the film when thermally loaded [17]. Coefficient of Thermal Expansion (CTE) of bulk materials is easily measured by dilatometry and is known for a large range of materials.…”

Section: Introductionmentioning

confidence: 99%

“…For aluminium alloys, it is reported in the literature that the CTE of anodic films measured by dilatometry is about 5×10 −6 K −1 [18]. Even if details on the experimental method employed to determine this value are not available, it has been used in numerous publications [17,19,20]. Nevertheless, more recently, Zhou et al [21] used X-ray diffraction to evaluate the CTE of anodic films under partially crystallized powder form (no influence of the substrate).…”

Section: Introductionmentioning

confidence: 99%

Investigations into the coefficient of thermal expansion of porous films prepared on AA7175 T7351 by anodizing in sulphuric acid electrolyte

Goueffon

Mabru

Labarrère

et al. 2010

Surface and Coatings Technology

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The aim of this study was to investigate the Coefficient of Thermal Expansion (CTE) of anodic films on 7175 T7351 aluminium alloy and to evaluate the influence of the film characteristics on this value. In particular, effects of porosity and post-treatments, such as coloring and sealing, were studied. Beam bending analysis was used as the experimental method and a numerical finite element model was developed to verify theoretical relationships hypotheses. In particular, the errors induced by the use of theoretical relationships between the curvature of the sample and stresses in the film were not negligible. A relation based on a finite element model was then developed and used to calculate stresses. The experimental value of CTE obtained by beam bending test was then validated by comparing the experimental cracking temperature of anodic films with a theoretical value directly depending on the previously determined CTE. The CTE of anodic films was found to be 13.0 ± 1.0 10 −6 K −1 independent from the porosity of the films and from the post-treatment (inorganic coloring and sealing).

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The cracking behaviors of anodic films on 1050 and 2024 aluminum alloys after heating up to 300°C

Cited by 11 publications

References 30 publications

In situ fabrication of blue ceramic coatings on wrought Al Alloy 2024 by plasma electrolytic oxidation

In situ fabrication of blue ceramic coatings on wrought Al Alloy 2024 by plasma electrolytic oxidation

Sustainable Surface Functionalization of Lightweight Materials : Cerium Oxide Nanoparticles Replacing Chromium in Anodic Coatings and Carbon Nanomaterials for Lightning Strike Protection

Investigations into the coefficient of thermal expansion of porous films prepared on AA7175 T7351 by anodizing in sulphuric acid electrolyte

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