Black PEO coating with enhanced thermal stability on titanium alloy and its thermal control properties

Black PEO Coatings on Titanium and Titanium Alloys Produced at Low Current Densities

“…PEO coatings obtained after 30 min have more pores of a smaller diameter, while with an increase in the processing time, there is also an increase in pores dimensions from nanometer to micrometer sizes, creating a channel structure. Yao et al [9] reported similar results, where after extending the reaction time, the nano-pores were stacked and connected to form the micro-pores and particular channel structure.…”

“…These coatings have significant implications for the spacecraft's successful operation in the extreme temperature conditions of space. They are applied to the surfaces of structural materials and are intended to have strong absorption and emission properties, frequently appearing as black coatings [9]. Black coatings are highly desirable in spacecraft internal components, notably electronic housing packages used for thermal regulation [10][11][12][13][14].…”

“…Yao et al investigated the effects of various additives (FeSO 4 , Co(CH 3 COO) 2 , Ni(CH 3 COO) 2 and NaWO 4 ) in phosphate-based electrolytes [39], the results of coating preparation without additives using a combination of silicate and phosphate-based electrolytes [40], and the influence of zirconium in two of their papers [41,42]. A more recent study of G5 titanium alloy can be found in the literature, authored by Yao et al [9]. This research focuses on the development of black coatings using a complex base electrolyte together with various additives (FeSO 4 , Co(CH 3 COO) 2 , NH 4 VO 3 ).…”

Plasma Electrolytic Oxidation of Titanium in Ni and Cu Hydroxide Suspensions towards Preparation of Electrocatalysts for Urea Oxidation

“…In the literature, black PEO layers are usually obtained for a Ti-6Al-4V alloy [ 20 , 26 , 60 ]. For their preparation, electrolytes containing Ni [ 26 ], Co [ 26 , 60 ], Fe [ 26 , 60 ], W [ 26 ] and V [ 60 ] are used.…”

“…In the literature, black PEO layers are usually obtained for a Ti-6Al-4V alloy [ 20 , 26 , 60 ]. For their preparation, electrolytes containing Ni [ 26 ], Co [ 26 , 60 ], Fe [ 26 , 60 ], W [ 26 ] and V [ 60 ] are used. However, it has been proven that the preparation of the black PEO coating does not have to be related to the presence of those ions in the layer and that black PEO layers can be prepared on pure titanium in a concentrated silicate solution [ 20 ], which is confirmed during our research: the basic PEO bath consisted of only KOH and Na 2 SiO 3 and the reference sample was still bluish-black, despite the lack of the mentioned ions in the oxidised material and in the electrolytic bath.…”