Study on Growth Mechanism and Characteristics of Zirconium Alloy Micro-Arc Oxidation Film

Ceramic coatings on R60705 zirconium alloy were prepared the surface by micro-arc oxidation (MAO) technique in electrolytes containing Na2SiO3, NaOH, and Na2EDTA. The growth behavior of MAO ceramic at different stages, including rate, microstructure, phase composition, was investigated using method direct observation boundary area. results showed that occurred both inward outward directions. At an time 5 min, thickness layer increased fastest, reaching 103.43 μm, with a rate 0.345 μm/s. After decreased tended to level off around 15 162.7 μm 0.181 μm/s, respectively. total continuously throughout process, always higher than thickness. composition mainly consisted monoclinic zirconia (m-ZrO2), tetragonal (t-ZrO2), small amount SiO2. main elements Zr, O, Si. corrosion resistance first then increasing time, current density 8.876 × 10−9 A·cm−2 indicating best resistance.