Characterization of miro-arc oxidation coatings on cast aluminum alloy doped with different Y₂O₃ particle concentration

Role of rare‐earth Y addition on formation and anticorrosion properties of MAO coating on 2024 aviation aluminum alloy

“…When Y(NO 3 ) 3 ·6H 2 O was increased to 1.5 g, the porosity reached a minimum value of 1.325% compared to other specimens, and the pores were covered by a large amount of melts. This was because the atomic percent of element Y increased to 1.72%, so that a large amount of Y(NO 3 ) 3 ·6H 2 O undergoes a chemical reaction during the growth of the coating to produce substances such as Y 2 O 3 that could enhance the denseness of the film 18 . With the addition of Y(NO 3 ) 3 ·6H 2 O up to 2.0 g, it can be seen from Figure 2E that although the Y‐element content of the coating surface decreases slightly, the pores start to become more, and its porosity rises by 4.38% compared with that of the 1.5 g‐Y specimen.…”

“…This high‐temperature, high‐energy environment helped Y(NO 3 ) 3 ·6H 2 O to be reacted to produce hard phase Y 2 O 3 particles, which enhanced the denseness of the coating and thus could improve the hardness of the coating 17 . Second, Y 2 O 3 particles could promote the transformation of γ‐Al 2 O 3 to α‐Al 2 O 3 , which also facilitated the increase of coating hardness 18 . Finally, the thickness of the coating increased under the influence of yttrium nitrate, and its hardness changed accordingly 19 .…”

“…17 Second, Y 2 O 3 particles could promote the transformation of γ-Al 2 O 3 to α-Al 2 O 3 , which also facilitated the increase of coating hardness. 18 Finally, the thickness of the coating increased under the influence of yttrium nitrate, and its hardness changed accordingly. 19 However, the reduction in hardness could be attributed to the generated coating being partially dissolved by a solution containing excess yttrium nitrate, and the production of hard phases would be reduced.…”

“…This was because the atomic percent of element Y increased to 1.72%, so that a large amount of Y(NO 3 ) 3 ⋅6H 2 O undergoes a chemical reaction during the growth of the coating to produce substances such as Y 2 O 3 that could enhance the denseness of the film. 18 With the addition of Y(NO 3 ) 3 ⋅6H 2 O up to 2.0 g, it can be seen from Figure 2E that although the Y-element content of the coating surface decreases slightly, the pores start to become more, and its porosity rises by 4.38% compared with that of the 1.5 g-Y specimen. It could be attributed to the fact that Y(NO 3 ) 3 ⋅6H 2 O had a certain solvency effect on the formed film layer, and when the electrolyte was added with too high a content of yttrium nitrate, its solution effect was greater than the promotion effect, which caused the quality of the coating to start deteriorating.…”

Photoluminescent Plasma Electrolytic Oxidation Coatings Containing YAG: Ce Produced on 1050 Aluminum Alloy

“…Indeed, it was demonstrated in the literature that, using DC, it is possible to obtain a thin PEO coating with a high porosity compared to ones achieved with pulsed current ( Ref 30,31). Pulsed current, instead, allows controlling micro-discharges on surface samples, leading to denser and thicker layers that improve corrosion resistance (Ref 32,33).…”