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RapidDirect Black Oxide Services
Create a uniform, matte black finish with a thickness of 0-30μm / 0-1181μin using our professional black oxide services and improve your metal part's appearance and corrosion resistance.
What's Black Oxide?
The black oxide coating process is a chemical conversion coating for ferrous materials, stainless steel, zinc, copper, and copper-based alloys, producing a uniform matte black appearance.
Black oxide coating services use a controlled coating process for a high-quality finish, which involves cleaning the part to remove contaminants that can prevent adhesion of the black coating and rinsing it to remove residual cleaning agents and contaminants.
Other preparatory processes include descaling for parts with rust or scale, neutralizing parts assembled or with blind holes, and deplating for plated parts.
Afterward, insert the metal part in solutions like sodium hydroxide, nitrates, and nitrites (depending on the part). Applying the black oxide coating on metal parts occurs at three temperatures, determining the coat.
At a hot temperature (141°C) and mild temperatures (90 – 120°C), there is a deposit of a magnetite coat (Fe2O3). At a cold temperature (20 °C – 30 °C), there is a deposit of a copper selenium coat (Cu2Se).
After applying the black oxide finish, base materials (except stainless steel or brass) undergo post-treatment using oil, wax, and lacquer. Oil gives a glossy finish, Wax provides a duller finish, and Lacquer dries quickly.
Black Oxide Specifications
| Applicable Materials | Visual Appearance | Industrial Applications | Thickness |
|---|---|---|---|
| Steel, Stainless Steel, Copper | Produces a uniform, matte black finish on the metal surface | Firearms, Fixturing, Gears, Molds, Pins, Tooling components | 0-30μm / 0-1181μin |
Advantages
- High aesthetic appeal due to the uniform, matte black finish.
- Minimize light reflection
- Suitable for parts with tight tolerance
- It prevents adhesive wear between parts that slide on contact.
Improved corrosion resistance
Notes
- It easily rusts and needs to be coated with anti-rust oil.
- Performed at high temperatures, it may affect the hardness of the material, not suitable for harder steels (above 50 HRC)
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FAQs
No, the black oxide treatment process produces a uniform matte black finish and is not available in other colors. However, if you need different colors, consider other surface finishing options.
Processes like anodizing, powder coating, or electroplating can provide a variety of colors and additional protective properties. These methods offer a broader range of aesthetic and functional finishes for metal parts.
To explore these alternatives and find the best solution for your specific requirements, consult a surface finishing services provider who can provide detailed information and recommendations.
Yes, black oxide coating typically necessitates a post-treatment to prevent corrosion. After coating with black oxide, treat the part with substances like oil, wax, or lacquer to enhance its corrosion resistance.
This post-treatment seals the porous black oxide layer, providing additional protection against rust and wear. However, parts made from corrosion-resistant materials like stainless steel or brass generally do not require such post-treatments, as they possess inherent resistance to corrosion.
It is essential to consult with a black oxide services provider to determine the most suitable post-treatment based on the specific material and application requirements.
No, the black oxide coating will not crack or fracture if the part is manipulated after application, as it becomes an integral part of the metal surface. The black oxide finish allows for some forming processes without compromising the part’s integrity. However, black oxide-coated parts can only tolerate minor manipulations. Extensive forming or heavy deformation might still damage the coating.
Yes, it is possible to apply black oxide selectively by masking the areas that do not need the coating. Masking involves covering specific sections of the part with materials that resist the black oxide process, ensuring only the exposed areas receive the coating.
Using this technique, you can have parts in different areas that require different finishes or properties.
Yes, powdered metal can undergo black oxide treatment. However, these parts typically require resin impregnation before the blackening process. Resin impregnation helps seal the porous surface of the powdered metal, preventing the black oxide solution from penetrating and weakening the material. Furthermore, it ensures a more uniform and effective black oxide coating.
No, black oxide treatment does not affect the surface hardness of heat-treated parts. It only forms a thin, protective layer on the metal’s surface without altering its underlying properties. Therefore, heat-treated parts retain their original surface hardness, strength, and corrosion resistance while preserving the base material’s mechanical properties
Yes, you can replate the blackened parts after removing the black oxide finish. The process typically involves stripping the existing black oxide coating and then applying the desired plating material. However, it’s important to consider factors such as the type of material being replated, the intended use of the part, and the specific plating requirements to ensure a successful re-plating process.
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