Email Us

Do You Know How Anodizing Works?

Anodizing, the process of forming an oxide film on aluminum products (anode) under the action of an applied current under the corresponding electrolyte and specific process conditions of metal or alloy electrochemical alumina and its alloys. Anodizing usually refers to sulfuric acid anodizing unless otherwise specified. In order to overcome the defects of surface hardness and wear resistance of aluminum alloy, expand the scope of application and prolong the service life, surface treatment technology has become an indispensable part of the use of aluminum alloy, and anodizing technology is the most widely used and most successful. 


What is anodizing?


The so-called anodization of aluminum is an electrolytic oxidation process, in which the surface of aluminum and aluminum alloys is usually transformed into an oxide film, which has protective, decorative and some other functional properties. The anodization of aluminum from this definition only includes the part of the process of forming an anodized film.


How Anodizing Works?


A metal or alloy product is used as an anode, and an oxide film is formed on the surface by electrolysis. Metal oxide films change the surface state and properties, such as surface coloration, improve corrosion resistance, enhance wear resistance and hardness, and protect metal surfaces. For example, aluminum anodization, aluminum and its alloys are placed in a corresponding electrolyte (such as sulfuric acid, chromic acid, oxalic acid, etc.) as an anode, and electrolysis is carried out under specific conditions and the action of an applied current. The aluminum of the anode or its alloy is oxidized, and a thin layer of aluminum oxide is formed on the surface, the thickness of which is 5-30 microns, and the hard anodic oxide film can reach 25-150 microns. Anodized aluminum or its alloy improves its hardness and wear resistance, up to 250-500 kg/mm2, good heat resistance, hard anodized film melting point up to 2320K, excellent insulation, shock resistance The breakdown voltage is as high as 2000V, which enhances the corrosion resistance and does not corrode for thousands of hours in ω=0.03NaCl salt spray. There are a lot of micropores in the thin oxide film layer, which can adsorb various lubricants. CNC anodized aluminum is suitable for the manufacture of engine cylinders or other wear-resistant parts; the film micropores have strong adsorption capacity and can be colored into various beautiful and bright colors. Non-ferrous metals or their alloys (such as aluminum, magnesium and their alloys) can be anodized. This method is widely used in mechanical parts, aircraft and auto parts, precision instruments and radio equipment, daily necessities and architectural decoration.


Generally speaking, the anode is made of aluminum or aluminum alloy as the anode, and the cathode is selected from the lead plate, and the aluminum and lead plate are placed in an aqueous solution, which contains sulfuric acid, oxalic acid, chromic acid, etc. An oxide film is formed on the surface. Of these acids, the most widespread is anodizing with sulfuric acid.

Related CNC Machining Services
Related News of CNC Machining
  • What Is the Difference Between Calcined Alumina and Aluminum Oxide?What Is the Difference Between Calcined Alumina and Aluminum Oxide?October 27, 2023In the refractory industry, calcined alumina and activated alumina are buzzwords, because they have become important synthetic raw materials for refractories, especially in some high-performance amorphous refractories. However, the difference between the two and whether the term is appropriate, there is ambiguity.view
  • What is CNC Turning and Milling?What is CNC Turning and Milling?October 24, 2022With the increasing number of types of CNC lathes, the names of many lathes gradually become difficult to understand. Next, let's understand what is CNC turning-milling compound. Before we underst...view
  • Gear Processing Process (7 Steps Make You Feel Simple)Gear Processing Process (7 Steps Make You Feel Simple)May 30, 2022One of the gear processing methods is the forming method, which is the method of cutting the tooth shape by using the forming milling cutter which is completely consistent with the shape of the tooth ...view
  • Machining tips and precautions in grooving and cutting offMachining tips and precautions in grooving and cutting offNovember 17, 2023​The cutoff and grooving process is an important part of CNC turning machining and presents many unique challenges. During the machining process, the limitations of machine tool and tool rigidity, cooling conditions, programming techniques, tool performance and many other factors can cause problems for machining efficiency, quality and safety.view
  • Which Is Easier to Weld, Aluminum or Stainless Steel?Which Is Easier to Weld, Aluminum or Stainless Steel?October 26, 2023This is because the melting point of stainless steel is higher than that of aluminum alloys, which makes it more stable during the welding process. Aluminum alloys are prone to the risk of being burned through because of their low melting point during the welding process. In addition, aluminum alloys are also susceptible to the formation of an aluminum oxide film on the surface in air, which has a much higher melting point than aluminum itself, making it more difficult to weld.view
  • How to choose the right material for cnc cnc machining parts?How to choose the right material for cnc cnc machining parts?November 1, 2023In the field of CNC numerical control machining, the correct selection of suitable materials is crucial to the performance, accuracy and durability of parts. Different environments and application scenarios require different types of materials, and the following will analyze how to choose the right material from several aspects.view
Tel
+86-0755-28025755
Address
1212, Zehua Building, Intersection of Longhua Meilong Road and Donghuanyi Road, Songhe Community, Longhua Street, Longhua District, Shenzhen, GuangDong, China