Types of Anodize
Clear Coat Anodize (Type 2)
Clear coat anodize is usually around .3 mils to 1.2 mils thick. While it is has less corrosion and wear resistant than type 3, it can be dyed almost any color. Expect a clean silver look for clear coat, much like a Macbook.
Hard Coat Anodize (Type 3)
Hard coat anodize is performed at lower temperatures and higher voltages than clear coat. These factors create a much stronger and thicker anodize layer. Expect high corrosion resistance and dielectric strength, along with a matte black finish.
AX200
AX200 is our proprietary coating that maximizes corrosion resistance and dielectric strength. Internal tests show about 10x corrosion resistance and 2x dielectric strength. Depending on the alloy used, color will range from dark gray to black.
Dye and Teflon Anodize
Along with the other anodize processes mentioned here. We also can dye or apply teflon over the anodize layer to give either color and lubrication properties, depending on the required application.
Approved LAM Anodize Specs
- 202-091770-001 and -002 Hard Anodized Aluminum coatings for Critical chamber components.
- 202-090140-001 Anodize Type 2, Black dyed
- 202-002950-001 Anodize Type 2 Clear anodize
- 202-002574-001 Hard anodize .002 thk. Critical chamber components
Approved Applied Materials Anodize Specs
- 0250-39693 Anodize coatings for Critical chamber components.
- 0250-01920 Hard anodize for ESC
- 0250-02018 8130 Pedestals Anodizing
- 0250-09059 Perf plates Anodizing
- 0250-09623 Oxalic Anodize
- 0250-09134 Susceptor Anodizing
Other Anodize Specs
- Mil-A-8625, Type 2 or Type 3, Class. 1 or 2 Natural, Black dye or Gold dye
- Semano AT4000: Tuffram/Symcoat equivalent
- Semano AX200
What sets us apart
Anodizing Basics and Spec Selection
Anodize Type and Class
Anodizing is an electrochemical process that transforms the aluminium into aluminium oxide which is highly corrosion resistant, insulating, and hard surface.
The process is usually carried out in a sulfuric bath where applied voltage and current density creates different characteristics in the anodize know as Type 2 or Type 3. After the initial anodizing, the part can undergo a dye process or simply sealed with Ni Acetate or DI Water. A dyed anodize part is called class 2 and a non dyed part is class 1.
Tolerances and Thickness
Most engineering drawings dictate that dimensions apply after anodize. This leads many machine shops to wonder how to compensate for anodize buildup. For this compensation you can assume that 50% of the anodize is penetration into the aluminium and the remaining 50% is buildup. Therefore, if the anodize is 2 mils, the part will be 1 mil thicker dimensionally.
Thickness can be anywhere from .1 mil to 5 mils (on 5052) or more commonly .1 mils to 3 mils on 6061. Clear coat thicknesses (Type 2) function best, especially for dye acceptance around .8 to 1.2 mils. Hardcoat (Type 3) needs around 1.8 mils to 3 mils. The thicker the anodize, the better the anodize properties which we will discuss now as it pertains to choosing a spec.
Choosing a Spec
Certain specs are designed to bring out certain attributes in the anodize, depending on customer needs. Common considerations are electrical resistance, corrosion resistance, thickness, cost, lubricity, and color.
While almost all process parameters can be modified to meet customer requirements, many customers choose MIL-SPEC 8625 as the standard given its reliable performance based on the anodize criteria and balances those performance attributes with a reasonable cost. As a default, any anodize jobs unspecified in terms of spec will be assigned Mil-Spec.
Performance Attributes
Corrosion Resistance
Dielectric Strength
Hardness/Wear Resistance
Color
Corrosion Resistance
6061 Anodizes black typically. 7075 anodizes gray. 5052 is also typically black.
Dielectric Strength
Similar to corrosion, AX200 is also the ideal spec for dielectric strength but the performance gap is not as high. Measured in volts, MILSPEC will provide about 600-700 volts of dielectric strength vs around 1,000 to 1,500 with AX200.
Hardness/Wear Resistance
The best wear resistance and hardness come from standard MILSPEC which is around 100 vickers harder than AX200. For a blend of hardness and increase wear resistance, consider AX300 which has similar hardness to MILSPEC with also the increased corrosion resistance.