Because it is robust and lightweight, aluminum is one of the most popular metals for manufacturing, and it can be used to make anything from cookware to automobile parts. Because anodizing this metal increases its resistance to corrosion and wear, many producers prefer to do so. Continue reading to find out what alternatives are available and how the procedure operates.
Aluminum Anodizing: What Is It?
Aluminum will spontaneously develop a very thin oxide layer when exposed to air, which protects the material for a brief period of time. An electrolytic technique called anodizing can increase this protection by thickening and organizing the oxide layer. The metal can be sealed or dyed thanks to the new anodized layer’s porosity. It’s a reasonably priced procedure that doesn’t require any specialized knowledge or tools.
Products that will be exposed to the weather and used outside frequently benefit greatly from anodizing. These consist of parts for outdoor furniture, electrical enclosures, bicycles, and automobiles. Additionally, because the coating is non-conductive, the material can serve as an insulator and becomes resistant to scratches. For this reason, it is also utilized in canoes, boats, architectural cladding, and even kitchenware. Because anodizing aluminum won’t react with substances that may otherwise discolor it, its sealed surface makes cleaning and maintenance easy.
How It Operates
An anodizing tank, a positive electrode (anode), and a negative electrode (cathode) are required to start the anodizing process. Cleaning and removing the aluminum’s natural oxide coating is the first step. After that, it is dipped into the anodizing tank, which contains a solution that conducts electricity. Positively charged aluminum ions are left behind after the aluminum’s electrons are released from the solution by zapping it with a current. The anode and cathode, which are able to conduct electricity but will not react with the electrolyte, complete the circuit with the electrolyte during the process. That electrolyte will often be something like sulfuric or chromic acid, depending on the sort of anodizing.
In order to form a glossy new thin coating of aluminum oxide, the electrons that exit the cathode contribute to the production of negatively charged oxygen ions, which then go to the aluminum’s surface and combine with the ions. By regulating the current density, duration, temperature, and electrolyte solution concentration, you may change the layer’s thickness.
Often called the barrier layer, the first oxide layer that forms is continuous and impermeable. However, the oxide layer gets more porous as it accumulates because it starts to impede current flow. This causes attachment points to form on the barrier layer, which grow into tiny, cylindrical holes that are orthogonal to the layer. The oxide layer is then forced to continue developing until it encounters the oxide layers of neighboring holes as the current begins to spread out from the center of each of those pores.
Various Procedures
This procedure comes in three different forms. These are as follows:
Analyzing with Chromic Acids
In this case, chromic acid serves as the electrolyte, resulting in the thinnest coating of all the techniques—2.5μ, or 0.0001 in., to be exact. But don’t let it deceive you. Despite being extremely thin, it gives the aluminum almost the same corrosion resistance as the other techniques. But this method’s drawback is that it’s less porous and doesn’t take color as well as the others.
Acid Sulfur Anodizing
This approach, which is likely the most popular, uses diluted sulfuric acid as the electrolyte, as you would have predicted. Its thickness ranges from 5.1 to 30.5μ, or 0.0002 to 0.0012in.
Hardcoat Anodizing
This kind still employs sulfuric acid as the electrolyte, but because it uses a greater voltage, longer immersion duration, and a lower bath temperature, it is made to create significantly thicker coatings (often between 12.7μ and 50.8μ or 0.0005 and 0.002in.). This coating tends to darken the aluminum a lot due to its thickness, but it can even be tougher than tool steel, making it ideal for high-wear circumstances. Because the pores are smaller and less responsive to dyes, coloring it is still possible but more difficult.
What Applications Does Anodized Aluminum Have?
Any application that currently uses another metal material may employ anodized aluminum. The following industries are served by Runsom’s anodized aluminum manufacturing:
Buildings
Anodized aluminum is a desirable material for stunning, contemporary building exteriors and interiors because it will never corrode, tarnish, or weather. For interior finishes like ceiling panels, store signs, and elevator panels, anodized aluminum is a stylish, lightweight, and reasonably priced choice since it can be custom-made in any color, gloss, or texture.
Moving around
Anodized aluminum works at any speed and is three times more durable than the raw material. Anodized aluminum provides transportation vehicles with the great appearance they want and the durability and weather resistance they want, whether it is used for rail car panels, commercial aircraft interiors, or sports car exterior brilliant trim.
Consumer Products
Customers seek durable, aesthetically pleasing goods that complement their tastes and way of life. Anodized metal can provide any desired texture, color, or appearance. Anodized aluminum provides the quality and adaptability that your customers want in consumer items like coffee makers, microwaves, and kitchen backsplash panels.
Anodized aluminum may be a stunning component of any project or product, whether you’re making high-end appliances, the newest model of luxury cars, artwork, or amazing skyscrapers and constructions. The anodizing technique is environmentally benign and yields a finish with unmatched dynamic beauty, durability, and endurance.