[L1] 1 Overview [L2] 1) Definition [L4] - A treatment method where the oxide film itself, created by intentionally oxidizing and corroding the metal surface (generally aluminum is applied as the base), plays a role in protecting the product from external influences. [L4] - Anodizing refers to the oxide film and the method where the aluminum surface is oxidized by oxygen generated at the anode to have strong adhesion with the cathode metal. [L4] - A compound word of Anode and Oxidizing. [L4] - The main material for anodizing is Al, but metals such as Mg, Zn, Ti, Ta, Hf, and Nb can also be anodized. [L2] 2) Types of Anodizing [L3] ① Soft Anodizing (Mild Anodizing) [L4] - Performed for decorative appearance and coloring. [L4] - Treatment Method: Dipping aluminum in a chemical solution and electrically oxidizing it to create a rough, porous, transparent oxide layer on the aluminum surface, then attaching dye to that surface. [L3] ② Hard Anodizing [L4] - Performed for wear resistance and electrical insulation. [L4] - Treatment Method: When electricity is passed through the metal in an electrolyte, oxygen is generated at the anode of the metal, and this oxygen oxidizes the metal surface to change it into Aluminum Oxide (Al2O3). Treatment that strengthens the surface strength of the metal by forming a film on the surface. [L3] ③ Plasma Electrolytic Oxidation (PEO) [L4] - A process where the growth of the film is caused by the movement of ions while generating arcs through dielectric breakdown. [L1] 2 Features and Applications of Anodizing [L2] 1) Features [L4] - Creation of oxides with excellent corrosion resistance. [L5] * Exerts corrosion resistance against weak acidity, hot water, deionized water, etc. [L4] - A method where the oxide film does not break, and ions move inside the oxide film by the applied electric field to grow the film. [L4] - Formation of decorative appearance (Soft Anodizing). [L5] * Can produce gloss and add color to the gloss. [L5] * Can form a beautiful decorative film on materials used for decorations or product covers. [L2] 2) Applications [L4] - Improvement of wear resistance of mechanical parts: Hard anodizing can form a thick film of 25~100 microns, so protection of the original material can be expected. [L4] - Granting lubricity: Lubricating performance can be granted during polishing after hard anodizing. [L4] - Improvement of coating adhesion: Capable of maintaining a solid film.