Formation of a corrosion-resistant coating on zinc by a duplex plasma electrolytic oxidation and conversion surface treatment

Properties of ZnO/ZnAl2O4 composite PEO coatings on zinc alloy Z1

“…This happens as a result of short-living microdischarges (milliseconds range), which take place under high voltages in low-concentrated, environmentally friendly electrolytes [ [4][5][6][7]. The oxide layers developed by PEO method are usually hard and well adherent to the substrates and can provide effective corrosion and wear resistance [ [8][9][10][11][12] ]. Thus, PEO treatments are well known for corrosion and wear protection of magnesium [ 5 , 7 , [15][16][17], aluminium [ [18][19][20][21][22][23] and titanium [ [24][25][26][27][28][29] ] based alloys.…”

“…Zinc also belongs to the materials, on which formation of PEO coatings is possible [ 9 , [51][52][53] ]. For example, a flash PEO treatment with post-sealing was performed for corrosion protection [ 9 ], formation of ZnO by PEO processing of Zn was studied because of its interesting combination of optical and electrical properties [ 53 ] as well as possible biomedical applications [ 52 ]. However, the total amount of studies regarding PEO of Zn alloys is very limited [ 52 ] and consequently also the knowledge about coating and phase formation in different electrolytes, coating properties and possible applications.…”