Comparative study of the effects of sealing processes on the wear resistance and the sealing quality of hard anodic coatings

Intermetallic particles distribution in 7XXX series aluminium alloy substrate impacts cathodic stability of silicate sealed anodized oxide

“…As a Cr(VI)-free alternative for anodizing, tartaric sulphuric acid (TSA) has been recognized as a promising solution [8][9][10][11]. Several Cr(VI)-free sealants have been proposed in the literature, such as common hot water sealing (HWS) or cerium salt bath sealing [11][12][13][14][15][16][17], as well as silicate sealants, notable for the capacity of silicate anion to be adsorbed inside the aluminium pores [17][18][19][20]. The microstructure and the corrosion resistance of these newly sealed layers formed with these emerging solutions need to be better characterized.…”

Archives of Metallurgy and Materials

“…An important role is played by the reaction of hydroxide precipitation by hydrolysis, which prevents leaching of the dye from the pores. However nickel salts are allergenic so this method has limited application [10]. Low-temperature sealing is carried out in nickel (II) fluoride solutions.…”