The effect of surface pre-conditioning treatments on the local composition of Zr-based conversion coatings formed on aluminium alloys

Cerezo, José María Palencia; Vandendael, Isabelle; Posner, R.; Wit, J.H.W. de; Mol, J.M.C.; Terryn, Herman

doi:10.1016/j.apsusc.2016.01.106

Cited by 49 publications

(46 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The coating formation process for Zr or Ti coatings involves activation of the surface in the acidic fluoride-containing bath and subsequent deposition of the coating. The deposition mechanism has been studied using open circuit potential (OCP) vs. time curves, 6,58,85,87,92,102 mass change, 6 Scanning Kelvin Probe (SKP) maps, 34,55,103 compositional analysis by Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS), 34 Rutherford backscattered spectroscopy (RBS), 49 glow discharge optical emission spectroscopy (GDOES) 49,104 and time-of-flight secondary ion mass spectroscopy (ToF-SIMS), morphological analysis 51,71,88,[93][94][95][96]103,105 and local pH measurements. 92,106 Aluminum parts are usually pretreated by alkaline etching and acid de-oxidizing.…”

Section: Deposition Mechanismmentioning

confidence: 99%

“…72,87,99,103 The consequent pH increase then creates the conditions for the deposition of oxides, which starts preferentially at the location of cathodic sites about 60 s after immersion (Fig. 3).…”

Section: Deposition Mechanismmentioning

confidence: 99%

“…in AA1050), Cu-rich particles will deposit on the surface and promote the formation of Zr-based coating. 87 The TecTalis coating containing Cu deposited on CRS was thicker compared to that without Cu (30 nm and 20 nm, respectively). 6 Copper was enriched, even up to 50−60 wt% at some locations.…”

mentioning

confidence: 95%

“…33,34,36,37,47,51,52,55,59,61,62,[64][65][66]69,70,72,78,82,84,87,90,92,94,95,98,99,101,102,104,[106][107][108]110,[112][113][114] Elevated temperatures were also studied, i.e. between 30 and 55…”

mentioning

confidence: 99%

“…Bath agitation.-In only a few studies 35,52,87,95,99,107 was the conversion bath agitated by stirring during deposition; most baths were stagnant. Recent studies have shown, however, that convection significantly affects the properties of the coating.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Review—Conversion Coatings Based on Zirconium and/or Titanium

Milošev

Frankel

2018

J. Electrochem. Soc.

148

113

View full text Add to dashboard Cite

There is a growing interest in conversion coatings based on titanium and/or zirconium as the result of the health and environmental issues associated with legacy chromate and phosphate conversion coatings. Any alternative technology should be environmentally friendly and cost effective, and also able to achieve comparable corrosion resistance and paint adhesion for ferrous and non-ferrous substrates. Conversion coatings based on titanium or zirconium seem to fulfill many of these requirements and thus offer a great potential for further applications. This literature review summarizes the scientific results in this rapidly growing area of research. Following the description of composition of conversion bath and deposition mechanism, the effects of process parameters for conversion baths such as pH, temperature, immersion time and agitation are presented together with coating characteristics. The effects of the type of substrate and substrate pre-treatment are explored for the most-studied substrates: Al alloys, zinc-coated steels and steels. Properties such as composition, morphology and thickness are summarized. The corrosion performance of the conversion coatings is discussed, as well as adhesion of organic coatings and delamination mechanism for a full coating system including substrate/coating/top-coat. Metals used in the construction of products and facilities in most applications, including industrial, infrastructure, transportation, construction, consumer goods, etc., are primarily selected from three groups: steels, zinc-coated (galvanized) steels, and aluminum alloys (AA).1 All of these materials require protection to prevent environmental degradation, and the most common approach to protection against corrosion is a multilayer coating system. Metal components are treated by a series of processes to create this coating system: cleaning, surface pre-treatment, and application of organic coating layers including primer and topcoat. Surface pre-treatments include anodizing (for aluminum alloys) and conversion coatings, which are the focus of this review. Conversion coatings are formed by immersion of a component in a chemical bath and reaction of the metal substrate with the components in the bath to form a layer that coats the surface. These layers provide some corrosion protection by acting as a barrier to the environment or releasing corrosion-inhibiting species. However, their primary role is to improve the adhesion of subsequently applied paint layers.The most important conversion coatings used for corrosion protection and adhesion promotion of ferrous and non-ferrous metal substrates are chromate conversion coatings (CCCs) and phosphate coatings. CCCs are highly corrosion protective. They consist of a backbone of chromium oxide/hydroxide with Cr in the 3+ oxidation state and also contain compounds with Cr in the 6+ oxidation state. 2-5The Cr(VI) provides the characteristic of self-healing, which is the ability to reform a protective coating after it has been breached by a mechanical or chemical proces...

show abstract

Section: Deposition Mechanismmentioning

confidence: 99%

Section: Deposition Mechanismmentioning

confidence: 99%

mentioning

confidence: 95%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Review—Conversion Coatings Based on Zirconium and/or Titanium

Milošev

Frankel

2018

J. Electrochem. Soc.

148

113

View full text Add to dashboard Cite

show abstract

Assessment of Mechanical and Optical Properties of Al 6060 Alloy Particles by Removal of Contaminants

et al. 2022

View full text Add to dashboard Cite

show abstract

Corrosion performance of powder‐coated aluminum profiles with increased trace element content

Lutz

Halseid

Graeve

2022

Materials & Corrosion

View full text Add to dashboard Cite

In this study, the corrosion susceptibility of powder‐coated Al6060 alloys with increasing Cu and Zn content is evaluated in a benchmark test. Although higher Cu and Zn limits would enable the industry to increase the use of end‐of‐life scrap and thus produce eco‐friendlier aluminum profiles, such alloys are often disregarded due to concerns of corrosion, especially filiform corrosion. Our results suggest that this concern is ungrounded as long as typical quality specifications for the pretreatment and coating process are followed and the alloy composition is kept within the limits of the European norm AW6060. Furthermore, we point out that the variation of the results due to processing at different coating production lines is larger than the difference between alloys of different Cu and Zn contents.

show abstract

The effect of surface pre-conditioning treatments on the local composition of Zr-based conversion coatings formed on aluminium alloys

Cited by 49 publications

References 30 publications

Review—Conversion Coatings Based on Zirconium and/or Titanium

Review—Conversion Coatings Based on Zirconium and/or Titanium

Assessment of Mechanical and Optical Properties of Al 6060 Alloy Particles by Removal of Contaminants

Corrosion performance of powder‐coated aluminum profiles with increased trace element content

Contact Info

Product

Resources

About