Passivation for Brass

1. Initial Cleaning

Before passivation, brass parts must undergo a thorough cleaning to remove grease, dirt, and oxidation layers. Our CNC machining ensures that brass parts have a high surface finish and precise dimensions, providing a perfect foundation for subsequent cleaning and passivation.

Degreasing: Using solvents or alkaline solutions to remove oils and lubricants.

Mechanical Cleaning: Abrasive blasting or brushing to remove surface contaminants.

Acid Cleaning: Using acidic solutions to remove oxides and rust spots.

2. Pre-treatment and Post-CNC Surface Preparation

After CNC machining, brass parts often need further pre-treatment to enhance the passivation effect. Our CNC machining not only precisely manufactures complex brass components but also ensures that the post-machining surfaces are uniform and smooth, making pre-treatment more effective.

Acid Cleaning: Further removing surface oxides for a purer surface.

Rinsing: Thoroughly washing the acid-cleaned brass parts with deionized water to remove residual acids.

3. Passivation Process

Depending on the chosen passivation method, brass parts are treated in passivation solutions for a specific duration. Our CNC machining ensures high precision and consistency of the part surfaces, enhancing the uniformity of the passivation process.

Chemical Passivation: Immersing brass parts in a chemical passivation solution, typically containing chromates or other oxidizers, forming a passivation film through chemical reactions. Precise control of treatment time and temperature ensures uniformity and thickness of the film.

Electrochemical Passivation: Using the brass part as an anode in an electrolytic solution, forming a uniform passivation film through electrochemical reactions. This method allows for more precise control over film thickness and properties, especially suitable for complex parts machined by CNC.

Nano Coating Passivation: Using sol-gel or spray methods to form a nano-scale protective film on the brass surface. This method is particularly suitable for applications requiring high corrosion resistance and surface hardness, perfectly complementing our precise CNC machining.

4. Post-treatment and CNC Machining Quality Assurance

After passivation, brass parts require proper post-treatment to ensure the stability and durability of the passivation film. Our CNC machining ensures consistency and high quality of the parts, making the post-treatment steps more straightforward and effective.

Neutralization: In some cases, using neutralizers to treat passivated brass parts to remove residual acidic or alkaline substances.

Rinsing: Thoroughly washing the passivated brass parts with deionized or pure water to prevent any residual substances from affecting the passivation film's performance.

Drying: Completely drying the brass parts to prevent water spots and oxidation.

5. Performance Testing and CNC Machining Quality Control

Passivated brass parts undergo performance testing to ensure they meet quality standards. Through our precise CNC machining technology and strict quality control measures, we guarantee the performance and durability of each brass part.

Salt Spray Test: Simulating a salt spray environment to test the corrosion resistance of brass parts.

Electrochemical Testing: Using methods like polarization curves and electrochemical impedance spectroscopy to assess the electrochemical properties of the passivation film.

Microstructural Analysis: Observing the microstructure and composition distribution of the passivation film using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).

By combining high-precision CNC machining with advanced passivation techniques, we ensure that every brass part is of superior quality, with excellent corrosion resistance, meeting all customer requirements.