Effect of organic additives in fluoacid-based Ti and Zr-treatments for galvanized steel on the stability of a polymer coated interface

Aluminum Protection by Using Green Zirconium Oxide Layer and Organic Coating: An Efficient and Adherent Dual System

“…The Zr oxide layer is usually formed by dip-coating of the metal substrates in aqueous hexafluorozirconic acid-based conversion solution (H 2 ZrF 6 ) [6]. The resulting films are typically very thin (<100 nm) [11][12][13][14] and their composition depends on the solubility and transport of ions in the bath solution (bath agitation) [6], bath additives and pH, with zirconium oxides and hydroxides being the main components of the passivating layer [6,[15][16][17][18]. For instance, Zoppas and co-workers [19] tested the efficacy of ZrO 2 obtained by dip-coating deposition (DC), as a sealing agent for aluminum anodized substrates.…”

Complementary corrosion protection of cast AlSi7Mg0.3 alloy using Zr-Cr conversion and polyacrylic/siloxane-silica multilayer coatings

“…These issues were reported for mild steel 36,39,40 , coldrolled steel 41 , carbon steel 42 and galvanised steel 31 using ZrCC coatings prepared from H 2 ZrF 6 and H 2 TiF 6 31 , Jiuhe Zr solution 41 and MAVOM 1742 coating 42 . As organic layers, epoxy coatings [39][40][41][42] , epoxy-containing ZnAl polyphosphate pigments 36 and polyester-based resins 31 were used. As additives to ZrCC, Zn sulphate 40 or various organic components were used 31 .…”

“…When analysing the literature data and commercial products, it should be distinguished that some ZrCCs contain only Zr-bearing components, while others also contain trivalent chromium salt. ZrCC conversion baths most often contain hexafluoro zirconic acid (H 2 ZrF 6 ) 12,21,22,25,[27][28][29] , but in some studies, potassium fluorozirconate (K 2 ZrF 6 ) 26 , and H 2 ZrF 6 and hexafluorotitanic acid (H 2 TiF 6 ) were used 29,31 . Some products also contain a small amount of cupric ions 27,28 for stimulating the precipitation of the coating, phosphate 26 or borate ions 21 .…”

“…As organic layers, epoxy coatings [39][40][41][42] , epoxy-containing ZnAl polyphosphate pigments 36 and polyester-based resins 31 were used. As additives to ZrCC, Zn sulphate 40 or various organic components were used 31 . The former acted as anti-corrosion pigments, whereas the latter initially improved the interfacial stability of conversion coating-treated substrates; however, in the long term, organic additives were shown to be detrimental to polyester coil coat adhesion.…”