Surface treatment technology after CNC machining

In modern manufacturing, the widespread application of CNC machining technology has greatly improved the accuracy and shape complexity of parts. However, the surface of parts after CNC machining often requires further processing to meet different performance and appearance requirements. Here are some common surface treatment technologies after CNC machining.

 

1. Spraying

Spraying is a common surface treatment method in which the paint is evenly sprayed on the surface of the part through a spray gun. Spraying can provide a variety of color options, while also protecting the surface of the part and preventing corrosion and wear. Different types of paint are suitable for different application scenarios. For example, anti-rust paint can be used to prevent metal parts from rusting, while decorative paint can add a beautiful appearance to the parts.

Before spraying, the surface of the part needs to be cleaned and pretreated to ensure that the paint can adhere well. During the spraying process, the thickness and uniformity of the spray should be controlled to avoid defects such as sagging and bubbling.

2. Electroplating

Electroplating is a method of depositing a layer of metal or alloy on the surface of a part using the principle of electrolysis. Electroplating can improve the corrosion resistance, wear resistance and conductivity of the part. Common types of electroplating include zinc plating, chrome plating, nickel plating, etc.

The electroplating process requires strict control of various parameters, such as current density, electroplating time, solution temperature, etc., to ensure the quality and thickness uniformity of the coating. At the same time, electroplating will cause certain environmental pollution, so effective environmental protection measures need to be taken.

 

3. Oxidation

Oxidation treatment is mainly used for surface treatment of metal parts such as aluminum and magnesium. A layer of oxide film is formed on the surface of the part through chemical reaction, which can improve the corrosion resistance and hardness of the part, and also improve the appearance of the part.

Anodizing is a common oxidation treatment method. In a specific electrolyte, the part is used as an anode and a dense oxide film is formed on the surface of the part by applying current. The thickness and performance of the oxide film can be controlled by adjusting parameters such as current density and oxidation time.

 

4. Polishing

Polishing is a processing technology that removes microscopic unevenness on the surface of the part through mechanical, chemical or electrochemical methods to make the surface of the part smooth. Polishing can improve the surface finish of the part and improve the appearance quality, while also reducing surface roughness and reducing the friction coefficient.

Mechanical polishing is the most common polishing method, which grinds and polishes the surface of the part by using tools such as sandpaper, grinding wheel, and polishing wheel. Chemical polishing and electrochemical polishing use chemical solutions or electrochemical effects to remove microscopic roughness on the surface of parts.

 

5. Sandblasting

Sandblasting uses high-speed sprayed sand particles to impact the surface of parts to remove impurities such as oxide scale, rust, oil stains, etc. on the surface, while giving the surface of parts a certain degree of roughness. Sandblasting can improve the adhesion of the surface of parts and provide a good foundation for subsequent spraying, electroplating and other treatments.

During the sandblasting process, it is necessary to select appropriate sand material and particle size, control the spray pressure and angle to ensure the uniformity and consistency of the sandblasting effect.

 

In short, the surface treatment technology after CNC machining is crucial to improving the performance and appearance quality of parts. Different surface treatment technologies are suitable for different materials and application scenarios. When choosing a surface treatment method, it is necessary to comprehensively consider the use requirements, cost, environmental protection and other factors of the parts to select the most suitable surface treatment technology.