6000T/M Micro-Arc Oxidation Line for EV Battery Trays This micro-arc oxidation (MAO) production line is designed for surface treatment of aluminum alloy battery trays used in new energy vehicles (NEVs). The line applies a high-voltage plasma discharge process in an alkaline electrolyte, forming an in-situ ceramic oxide layer — primarily α-Al₂O₃ — directly on the aluminum substrate. Unlike conventional anodizing, the MAO coating is fully integrated with the base metal,