7 Major Surface Treatment Processes for Metal Materials

The surface treatment process of metal materials usually refers to the use of modern physics, chemistry, metallurgy, and heat treatment methods to change the surface state and performance of parts, so that they can be optimized with the core materials to achieve our predetermined performance requirements.

The role of metal surface treatment

1. Improve the corrosion resistance and wear resistance of metal surfaces, slow down, eliminate, and repair changes and damage on the surface of materials.

2. Use ordinary materials to obtain surfaces with special functions;

3. Save energy, reduce costs and improve the environment

Technical classification of metal surface treatment

1. Surface strengthening treatment

2. Surface cleaning treatment

3. Surface decoration treatment

4. Surface anti-corrosion treatment

5. Surface repair treatment

7 surface treatment processes

Polishing

Polishing refers to the use of mechanical, chemical, or electrochemical effects to reduce the surface roughness of a workpiece to obtain a bright and smooth surface. Polishing cannot improve the dimensional accuracy or geometric accuracy of a workpiece, but it can obtain a smooth surface or mirror gloss. In addition, this process is sometimes used to eliminate the surface gloss of metal materials. Usually, the polishing process uses a polishing wheel as the main tool.

Spray paint

Spray painting is a process that uses a spray gun to disperse paint into fine droplets with the help of air pressure and apply it to the surface of the object to be painted. Spray painting can be divided into air spray painting, airless spray painting, and electrostatic spray painting. When spraying paint, special attention should be paid to construction safety to avoid inhaling mist or allowing mist to contact with human skin.

Powder spraying

Powder spraying is a coating process that uses the corona discharge phenomenon to make powder coating adhere to the workpiece. This process uses electrostatic adsorption to evenly spray the powder coating onto the workpiece surface to form a uniform powder layer, which is then heated to melt, level, and solidify the powder, ultimately forming a hard and uniform coating on the workpiece surface.

Sandblasting

Sandblasting is a process that uses the impact of high-speed sand flow to clean and roughen the surface of the substrate. Sandblasting can be divided into dry sandblasting and wet sandblasting. Due to the impact and cutting action of the abrasive on the workpiece surface, the workpiece surface obtains a certain degree of cleanliness and different degrees of roughness, and the mechanical properties of the surface are improved, thereby improving the fatigue resistance of the workpiece, increasing the adhesion between them and the coating, and extending the durability of the coating.

Brushed

The metal brushed process is a manufacturing process that uses sandpaper to repeatedly scrape fine lines on the profile. It is mainly divided into three steps: degreasing, sanding machine, and water washing. In recent years, more and more products use the wire drawing process on the metal appearance to achieve beautiful and corrosion-resistant effects. This process can make the profile surface have both fashion and technological elements.

Chrome plating

The chrome-plated layer is a silvery-white metal with a slight bluish tint. Metallic chromium is easily passivated in the air, and a very thin passivation film is formed on the surface, thus showing the properties of a precious metal. The chrome-plated layer has good chemical stability, high hardness, and good heat resistance. The friction coefficient of the chrome-plated layer is small, especially the dry friction coefficient.

Anodizing

Anodizing is an electrochemical process that enhances the corrosion resistance, wear resistance, and insulation of metals by forming an oxide film on the metal surface. The process is to place the metal in an appropriate electrolyte and apply an external current to form an oxide film on the metal surface. This oxide film has the characteristics of high hardness, high corrosion resistance, and high insulation, which can protect the metal surface from environmental erosion and improve the wear resistance and corrosion resistance of the metal.