Effect of Surface Prefabricated Micro-groove on the Structure and Properties of Cast Aluminum Alloy Micro-arc Oxidation Ceramic Coating

In order to explore the influence of surface prefabricated micro-groove on micro-structure and properties of micro-arc oxidation ceramic coating of cast aluminum alloy, a micro-arc oxidation film was prepared on the surface of ZL108 aluminum alloy. Scanning electron microscopy, X-ray diffraction, digital microhardness tester, multi-function surface performance tester and electrochemical workstation were used to test the morphology and performance of the coating. The results show that compared with the coating formed on the smooth sample, the coating formed on the micro-groove sample was thicker and more rigid. However, due to the concentrated discharge at the micro-groove location and the high energy, the coating was porous and its adhesion and corrosion resistance were worse. Therefore, although the surface micro-groove makes the coating quality decrease slightly, it can improve the energy of micro-arc oxidation discharge and increase the coating formation rate.