Anodizing aluminium profiles means growing a protective oxide layer. The anodizing process steps are as follows: profiles are placed in an immersion bath containing acid, which in turn leads to advantages like an improved protection of the metal. The metal serves as an anode, which is why we call this surface treatment anodizing. Mifa uses anodization to increase the overall quality of extrusion products.
Layer thicknesses from 5 to 20 µm can be achieved depending on the application of the profile, the desired layer properties, and other parameters. Only 1/3 of the oxide layer is built up; the rest penetrates the aluminium during anodizing. It is important to carefully consider this during the design phase, in order to get the highest quality anodized aluminium extrusions.
Surface treatment to improve products
Surface treatments improve your magnesium or aluminium components. Corrosion cannot take place, and wear resistance increases while friction decreases. When aluminium profiles are visible, an attractive surface is essential. Coatings can also provide this. All custom aluminium extrusion profiles benefit from an optimal surface treatment. Mifa can perform many different surface treatments. And if necessary, we can develop a tailor-made coating.
Mifa Surface Treatment focuses entirely on surface treatments for various markets, such as the automotive and aerospace industries.
Types of aluminium anodizing
At Mifa, we have three methods to anodizing aluminium profiles:
Almost all aluminium alloys can be anodized. The alloy is a determining factor for the colour of the anodized part. An alloy of the 3000 series turns grey, and a 7000 alloy turns gold. At Mifa however, we can supply the protective oxide layer in different colours. Black or orange are included in our package as standard. Other colours are always possible on request. Of course, you can also receive your anodized aluminium extrusion untreated and colorless. Here you will find more information about the different types of anodizing.
GLISSCOAT®
GLISSCOAT® 2083 is an anodic layer with a reduced friction coefficient. This variant is similar to hard anodizing, though GLISSCOAT® 2083 has a significantly lower friction factor.
The coating was originally designed to minimize the slip-stick effect in motorcycle shock absorbers. Nowadays, it is also used in machinery manufacturing and the pneumatic industry.
Thanks to a finishing process with fluoropolymers, not only is the surface roughness reduced, but corrosion protection is also enhanced. GLISSCOAT® 2083 can be tinted black.
HART-COAT®
HART-COAT®, often referred to as HC, is a hard electrolytic oxidation coating that protects aluminium alloys with a hard layer resembling ceramic. It safeguards against wear and corrosion. The surface treatment, also known as 'hard anodizing', has two main objectives:
- Enhance the properties of various components.
- Improve visual attributes.
HART-COAT® coatings are formed by anodic oxidation in a cooled acid electrolyte of special composition. The resulting layer has fewer pores than those produced by traditional anodizing processes, and the pores have a smaller diameter.
Half of the oxide layer forms on the surface, while the other half penetrates the aluminium. It's best to consider hard anodizing during the design phase. Our team of experts is happy to provide further advice. However, keep in mind that the color of the anodized piece is determined by the alloy.
HART-COAT® can be used in a wide range of areas, such as:
- Machinery & Equipment
- Automotive
- Household appliance industry
- Medical equipment
- Pharmaceutical industry
- Defense technology
Technical Anodizing
Technical anodizing, also known as normal anodizing, is designed to enhance both the functional and decorative qualities of aluminium and its components.
This process involves anodic oxidation in a cooled acid electrolyte of special composition. Using a direct electric current, the base material on the surface transforms into an aluminium oxide layer.
The desired thickness of the layer depends on its intended use, the desired properties of the layer, and other factors. Typically, a thickness between 5 and 20 µm is achieved. Only a third of this oxide layer forms on the surface, while the rest penetrates the aluminium. This is a factor to consider during the design process.
As with HART-COAT®, the color of the anodized part is strongly influenced by the alloy. For example, an alloy from the 3000-series results in a gray shade, while an alloy from the 7000-series has a golden appearance.
Anodizing layer properties
|
MAX. LAYER THICKNESS |
up to 20 µm |
|
CORROSION PROTECTION |
Max. 2,000-hour salt spray test – in conformance with DIN 50021 ESS |
|
HARDNESS |
approx. 250 HV 0.025 depending on the alloy |
|
GENERAL STANDARD |
MIL-A-8625F Type II |
Industrial coating for magnesium alloys
In addition to aluminum, we also anodize magnesium. For this purpose, we use MAGOXID-COAT®. MAGOXID-COAT® is a plasma-chemical surface treatment for improving magnesium alloys. The coating is applied in an electrolytic salt solution.
This surface treatment is a crystalline oxide ceramic with a high proportion of highly resistant compounds such as spinels, for example, MgAl2O4. The plasma-chemical process results in ceramic coatings that meet additional requirements in addition to wear-resistant and corrosion-resistant oxides, such as:
- Hardness
- Contour accuracy
- Flexural strength
- Dimensional stability
- Temperature stress
Mifa renews AS 9100 certificate
The aviation industry imposes strict quality and safety requirements on manufacturers and suppliers. Since 2013, Mifa has held the AS-9100 quality certificate for the aerospace industry, and we are proud to announce that the certificate has been renewed for the upcoming years.
The renewal of the AS-9100 certificate demonstrates that Mifa and Mifa Surface Treatment prove that Mifa's production and business facilities meet the high-quality standards required by the aviation industry.
Case: Coloured anodizations for SodaTASTE
Through co-engineering, we created various prototype pressure cylinders for SodaTASTE, utilizing our expertise in coloured anodization. SodaTASTE is a progressive company in the beverage sector, specializing in soft drink flavours using CO2 cylinders.
SodaTASTE approached Mifa via Aalberts Surface Technology because Mifa is the only one among the Aalberts companies to have a Bright Dip process. This treatment imparts a clear shine to anodized aluminium profiles and is often combined with techniques such as blasting or grinding.
Our engineers, with their profound knowledge of aluminium extrusion, adjusted various specifications for the prototypes, including:
- Various colours;
- Specific etching steps;
- Process variations;
- Process settings.
For the testing phases, several tanks were installed in our automatic anodizing line. At Mifa, we also have the capability to maintain anodizing layers in a range of colours for future projects.
Thanks to co-engineering, we developed new colour baths for this project. SodaTASTE's vision was merged with Mifa's expertise and innovative technologies, resulting in new colour baths for optimally coloured and anodized aluminium extrusion products.
Would you like to know more about anodized aluminium profiles?
We understand that you may want to learn more about the anodizing of aluminum. We would be happy to provide you with more information. The easiest way is to fill out the contact form. We will then get in touch with you as soon as possible.
