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anodizing aluminum coating

Aluminum Coating: Choosing the Right Finishes for Your Aluminum Parts

Aluminum is a versatile metal with excellent mechanical properties and extensive applications in various industries that require precision CNC-machined aluminum parts. Aluminum components often come with good surface quality.

However, manufacturers often improve the quality of these components with quality aluminum coating. For optimum results, you must choose the right surface finish to enhance these parts with better aesthetic enhancement, better physical properties, resistance to rust, wear, and chemicals, etc.

This guide discusses the common aluminum finishes and helpful considerations for choosing the ideal surface finish for your aluminum machined parts. Let’s get to it!

Top 7 Types of Aluminum Finishes to Elevate Your Projects

Aluminum coatings are different surface treatments manufacturers and product designers commonly use to protect aluminum alloys from high heat, abrasion, chemical reactions, and humidity. Below are different types of aluminum coatings suitable for your project:


al7075 beadblast hard anodizing
AL7075_BeadBlast_Hard Anodizing

Anodizing is an electrochemical process that enhances abrasion and corrosion resistance in aluminum parts by thickening the natural oxide layer to form a dense film. The aluminum coatings become thicker depending on the time the aluminum spends in the anodizing tank containing electrolytic solution.

More importantly, anodized aluminum offers several desirable benefits, such as dye adhesion, vibrant colors, and better heat dissipation in aluminum machined parts. Below are the different anodizing types:

  • Clear Anodizing

Clear anodizing is an anodizing finish that doesn’t involve using dyes. Clear coating is more forgiving, unlike darker anodized colors, which usually exhibit color inconsistency and disfigurations when installed on-site.

  • Dyed Anodizing

This involves dying the anodic film into any color to achieve a decorative finish after the anodizing process. This dyeing process provides a vibrant finish on the aluminum part. Anodized aluminum absorbs the dye through the pores of the aluminum oxide layer when immersed in a dye bath. It allows you to achieve a range of colors that best fit the requirements of your parts.

  • Hard, Clear, and Dyed Anodizing

Hard, clear anodizing offers greater corrosion and wear resistance in aluminum products. Although it is similar to regular anodizing, its oxide layer is thicker and more durable on an aluminum surface. Hard clear anodizing is commonly used to achieve a clear finish with enhanced durability in aluminum products.

Conversely, hard-dyed anodizing provides a thicker and more robust coating with a wide range of color options added through dyeing. As a result, it helps to enhance the durability of aluminum parts and achieve a specific color for your custom aluminum parts.

  • Blasting + Anodizing

Blasting and anodizing are a combination of two processes commonly used to prepare and anodize aluminum parts. The blasting process involves using an abrasive media such as glass beads or sand to remove imperfections or contaminants from the surface of aluminum components.

Then, you can anodize the prepped aluminum surface to achieve the desired coating. This anodizing process forms a smooth, high-quality oxide layer on the aluminum surface.

Powder Coating

powder coating
Powder Coating

Powder coating is a surface treatment that provides shiny, long-lasting colors with excellent resistance to ultraviolet rays in various metals. You must clean and prep the aluminum parts, then spray the powder coat with an electrostatic gun to apply the dry paint powder on the metal surface. Then, you must bake the powder-coated aluminum parts to melt and cure the coating to achieve a uniform finish.

al5083 h111 conversion coating powder coating
Al5083 H111 Conversion Coating Cowder Coating

Powder coatings are not as hard and long-lasting as anodized aluminum. However, powder coatings provide an excellent appearance and corrosion resistance. Unlike liquid painting, the powder coating technique is non-toxic since it lacks solvents comprising volatile organic compounds (VOCs).

Chemical Conversion Coating

aluminum alodine chromate conversion coatings
Aluminum Alodine Chromate Conversion Coatings

Chemical conversion coating or alodine finish is an inexpensive alternative to anodizing. Chromate chemical conversion is suitable for improving the passivating oxide layer on the aluminum parts’ surface. It provides excellent corrosion resistance and an aesthetically appealing exterior.

Moreover, chemical conversion coatings provide high electrical conductivity in aluminum machined parts in applications that require high electrical conductivity. However, alodine solution has low environmental sustainability compared to other finishes.

Chrome Plating

aluminum chrome plating part
Aluminum Chrome Plating Part

Chromate plating is widely embraced in consumer goods and manufacturing industries. It uses an electrolytic process to form a protective aluminum layer and bright luster on the surface of the aluminum part by submerging it in an electrolytic bath. Chrome plating is especially suitable for decorative purposes or enhancing the preferred properties of machine parts.

Below are the two types of chrome plating that offer the preferred surface finish for metals:

  • Hard Chrome Plating

Hard chrome plating, or industrial or engineered chrome, involves immersing a metal part in a chromic acid solution. It is usually thicker than the decorative type and ideal for various industrial applications that require great strength, wear, and corrosion resistance.

Hard chrome provides a durable thickness that reduces friction between machine parts, improving components’ durability and performance. More importantly, industrial chrome ensures machine components’ extended lifespan and reduces downtime and maintenance expense risks.

  • Decorative Chrome Plating

Decorative chrome plating improves the aesthetic appeal of aluminum parts with its thin layer of chromium asides protecting the base material from corrosion and wear. This chrome plating doesn’t offer the same durability levels as the hard chrome plating.

However, it is easy to clean, provides some corrosion and wear resistance, and improves your metals’ aesthetic appeal. Its typical applications include kitchen utensils, car parts, and tools.

Polyvinylidene fluoride (PVDF)

kureha polyvinylidene fluoride pvdf kf polymer

Polyvinylidene fluoride (PVDF) coating is a typical resin-based aluminum coating entrenched with color pigment particles. They are best applied on aluminum machined components in a factory setting and provide an extensive range of matte-finish colors. These coatings offer extreme hardness and high insolubility, allowing them to protect metal substrates from corrosion.

PVDF coatings ensure your metal surfaces exhibit excellent resistance to fading, chemicals, and corrosive substances. Hence, these aluminum coatings are ideal for exterior applications such as aluminum wall cladding. More importantly, you do not need an oven to cure PVDF coatings, and these coatings do not contain toxic VOCs like liquid painting.

Teflon Coating

Teflon or PTFE coating is excellent for different applications ranging from automotive, electronics, pharmaceutical, aerospace, optical devices, and cookware. Teflon coating has a high molecular weight, which makes it resistant to water.

Product engineers often choose this coating because of its long list of benefits, including outstanding electricity insulation, ultraviolet ray resistance, doesn’t absorb water, and can withstand extreme temperatures.

Its high chemical resistance property makes it a well-suited coating for aluminum components in the medical industry. It is suitable for coating tubes, pipes, and vessels. Similarly, its low-friction co-efficient property makes it an ideal aluminum coating in automotive and industrial applications.

Electrophoretic Coating

e coating aluminum alloy parts

The electrophoretic coating or E-coat process involves submerging the aluminum product in a bath of coating material and using an electric current to apply the coating on the surface. It provides your product with good resistance to corrosion and chemicals.

This aluminum coating type is straightforward and inexpensive, making it a popular choice in industries like the automotive industry. This coating solution allows you to combine other coatings to enhance its performance further.

Choosing the Right Finish for Your Project

hard anodizing aluminum parts
Hard Anodizing Aluminum Parts

It would help to know that the aluminum part protection that these processes offer often varies from bright and mirror-like to rough or patterned. Therefore, it is advisable to understand these surface finishes to determine the one that best enhances your products. It would help to choose a finish that meets your application’s quality standards and ensures the aluminum part fits and functions well.

The aluminum metal’s versatility makes it compatible with an extensive list of applications, including automotive, aerospace, marine, defense and military, and consumer products. However, it is crucial to consider environmental factors when choosing aluminum coatings for your project, especially if your product is meant for outdoor use.

It would help to consider environmental factors that can affect aluminum parts in the long run, such as humidity, temperature, sunlight, ultraviolet rays, etc., when choosing a finish for aluminum machined parts for outdoor applications. Choose a finish that ensures the extended life span of aluminum machined parts even when exposed to environmental factors.

Nevertheless, ensure that the chosen aluminum coating fits your budget without sacrificing quality. More so, your budget should guide your choice of a finish while having quality in mind because choosing a costly finish may increase the product’s machining cost.

Elevate Your Projects with Expert Aluminum Finishing

at machining surface finishing services 1
AT-Machining Surface Finishing Services

Aluminum coating is fundamental to your custom aluminum parts because it helps to elevate these products from “basic” to “superior.”   Besides, partnering with an aluminum finishing expert is crucial in achieving the best results when producing aluminum parts. Therefore, you must understand these finishes to choose the ideal one for your products and intended application.

AT-Machining offers expert aluminum finishing at the best prices that fit within your budget. Our team of expert product designers, engineers, and quality control experts ensures your aluminum parts get the right finish that meets the intended application’s demand. Contact us today to elevate your project to the desired quality standard. Upload your CAD file now for an instant quote!

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