Anodizing is a common surface finishing technique used for aluminum components. It helps to improve part performance and enhance aesthetics. By converting the metal surface into a hard and durable finish, aluminum anodizing prevents corrosion and wear resistance.
As a newbie or seasoned manufacturer, it is not a surprise if you wonder whether anodizing makes the final parts stronger. While anodizing improves durability, it has no significant effect on the metal’s core strength. Read on to find out why anodizing does not make aluminum parts stronger and a comparison with other common surface finishing operations.
What is Anodizing
Anodizing is a surface finishing technique carried out usually after fabricating a part. It is an electrochemical process that converts the metal surface into a strong and durable oxide finish. This process is mainly used for aluminum alloys. However, it is also suitable for other nonferrous metals such as zinc, titanium, and magnesium.
The process of anodizing begins with proper cleaning and preparation of the workpiece surface. You clean using an alkaline or neutral agent to remove dirt and grease that can interfere with the anodizing process. Thereafter, immerse the prepared piece into an electrolyte solution which is usually sulfuric acid. You then pass an electric current and wait for the oxide layer to form on the surface.
The final step in anodizing involves sealing using hot water or nickel acetate solution. You can choose to dye the anodized aluminum parts to create a variety of colors before sealing it.
Does Anodizing Make Aluminium Parts Stronger
Though anodizing enhances many of the properties of aluminum components, it does not have a significant influence on the bulk mechanical strength. The anodic layer is itself more durable and stronger than the part. However, the process does not affect the intrinsic properties of aluminum.
This is because aluminum’s strength properties are mainly determined by the alloy’s composition and fabrication technique used. Anodizing is a surface treatment and the layer grows outwardly. It does not penetrate deep and will not change the workpiece characteristics. Instead of increasing strength, what anodizing does is improve surface hardness. As a result, the final anodized part is more resistant to abrasion and scratches.
Why Use Anodizing for Aluminum Parts
Though anodizing does not increase the strength of aluminum parts, it offers many other benefits. The following are some advantages of aluminum anodizing.
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Corrosion Resistance
Anodizing improves the corrosion resistance properties of aluminum parts. The oxide layer it creates is stable and can withstand corrosive attacks from both the environment and chemicals. This layer acts as a barrier and prevents further oxidation of the aluminum substrate. This feature makes it possible to use aluminum components in demanding outdoor applications.
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Aesthetic Enhancement
Another benefit of using aluminum anodizing is the beautiful appearance of the final parts and components. Anodizing enhances aesthetic appeal and makes a product sell more. Furthermore, there is a wide variety of dye colors you can use for anodized aluminum. Anodizing creates a porous layer that can absorb dye that you then seal to produce vibrant hues.
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Electrical Insulation
The electrical insulation properties of anodized aluminum are second to none. When compared to the original metal itself, the anodic layer does not conduct electricity readily. It prevents the passage of electric current. The layer is thick and ensures consistent electrical insulation. As a result, you can use anodized aluminum when manufacturing electrical and electronic structures.
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Durability
Anodizing may not make aluminum stronger in many instances. However, you can be sure of increased hardness and durability, The aluminum oxide layer grows out of the metal and is a part of it. Hence, it does not peel or flake easily even after extended use. The final aluminum parts made using the anodizing technique are resistant to heat and wear. You will experience less damage and scratches when compared to untreated metal.
Comparison to Other Surface Treatment
There are other surface treatment options you can use for aluminum components. Let’s compare them with the anodizing technique in terms of corrosion resistance, durability, and aesthetics.
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Electroplating
Electroplating is a common surface finishing operation you can employ for aluminum parts. This technique deposits a thin layer of metal including nickel, chrome, gold, and silver to the component. To carry out electroplating, you immerse the workpiece into a solution containing metal ions before introducing an electric current. When compared to anodizing, electroplating provides a finer finish. However, the plating is not as thick and durable as the anodic finish.
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Painting
Painting is a versatile process that improves the appearance and performance of many parts across manufacturing industries. Here, you apply a liquid coating to the surface of the workpiece either by spraying or using a brush. Painting aims to protect the parts when you use them in demanding conditions. It is simple and offers a wider range of colors than anodizing. However, anodizing is more wear and corrosion-resistant.
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Powder Coating
Powder coating is similar to liquid painting. However, it is a dry process where you apply free-flowing and loose powder particles on the surface of the workpiece. The powder particles are electrically charged and fuse to the surface of the part to create a durable and strong finish. Though powder coats are usually thicker, the anodic layer is harder and more integrated. Hence, anodized aluminum parts perform better in extreme environments.
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Passivation
Passivation is a chemical finishing process that removes free ions from the workpiece surface to create a micro coating. To carry out the passivation technique, you treat the metal with citric or nitric acid to form a passive oxide layer. This process eliminates surface contaminants, increases corrosion resistance, and extends the lifespan of the components. When compared to anodizing, this technique does not change surface characteristics and is less protective.
Conclusion
Anodizing is a surface finish option that improves the way aluminum parts function. While it enhances durability, anodizing does not make aluminum components stronger or weaker. This is because this technique acts on the surface and has no influence on the core strength. The ano layer itself is harder and more durable when compared to the substrate. The layer grows outwardly which makes the part suitable for use in many applications. When considering outsourcing your metal fabrication needs, try Zintilon today for the best and most reliable services.