Preparation of wear-resistant ceramic coating by dynamically controlling the resistance during MAO

Micro arc oxidation (MAO) is a surface treatment technology that typically involves immersing the valve metal in an electrolyte to generate a ceramic coating for improved surface characteristics. This paper proposes a novel MAO g48 the need for electrolyte immersion. The MAO power supply's positive electrode is connected to the valve metal as the anode, while the negative electrode is connected to a stainless-steel wire in the electrolyte circulation system. The distance between the cathode and anode is dynamically adjusted using a mechanical arm. Through advanced techniques like X-ray diffraction and X-ray photoelectron spectroscopy, successful ceramic coatings comprising alpha-Al2O3 and gamma-Al2O3 phases on aluminum substrates were achieved. Tribological experiments demonstrated that coatings prepared with a cathode-anode distance of 1.0 cm exhibited a scratch width of approximately 286.160 mu m, while a distance of 3.0 cm resulted in approximately 1736.80 mu m. This highlights the significant impact of the cathode-anode distance on the wear resistance of the plasma electrolytic oxidation ceramic coating, with optimal performance observed at 1.0 cm. Utilizing a robotic arm to control the cathode movement enables effective surface treatment of large workpieces and targeted regions, addressing practical challenges in MAO applications.