What specific changes can Dalian sandblasting bring to metal surfaces?

Dalian sandblasting processing is a widely used surface treatment technology that plays an important role in various industrial fields. It can improve the surface quality and performance of workpieces, reduce material loss and manufacturing costs, and promote the development and progress of the industry. With the continuous advancement of technology and the continuous development of industries, sandblasting processing will be increasingly widely used in the processing and surface treatment of various materials, creating a better living and working environment for humanity.

Sandblasting technology can be used to process material surfaces at the micro and nano scales. By precisely controlling parameters such as abrasive particle size, spray pressure, and angle, surfaces with micro nano structures can be manufactured for use in fields such as microsensors and microfluidic devices. For example, in the production of microfluidic chips, sandblasting can form specific textures on the surface of the chip channel, change the surface wettability, and thus affect the flow characteristics of the fluid.

What specific changes can Dalian sandblasting bring to metal surfaces?

1、 Clean the surface

Remove rust and oxide scale

When metals are exposed to air or humid environments for a long time, rust (such as iron oxides) and oxide scales will form on the surface. Sandblasting processing utilizes the impact of high-speed abrasives to effectively remove rust and oxide scales from metal surfaces. For example, for steel products, sandblasting can penetrate deep into the interior of rust and oxide layers to peel them off. Like steel structural components used in construction, after sandblasting treatment, the rust and oxide layer on the surface are removed, restoring the original luster of the metal.

Remove oil stains and impurities

Metal surfaces may be contaminated with impurities such as oil, dust, and old coatings during processing, transportation, or storage. During sandblasting, the erosion of abrasives can remove these oil stains and impurities from the metal surface. For example, on the surface of metal parts after mechanical processing, there is often residual cutting oil. Sandblasting can thoroughly remove these oil stains, providing a clean surface for subsequent processing such as electroplating and painting.

2、 Change surface roughness

Roughened surface

Sandblasting processing can make metal surfaces rough. When abrasive particles collide with metal surfaces, they form tiny pits and scratches on the surface, thereby increasing surface roughness. The increase in roughness is beneficial for improving the adhesion between the coating and the metal surface. For example, before painting automotive parts, sandblasting is used to roughen the surface, allowing the paint to better adhere to the metal surface and prevent peeling, thereby extending the service life of the coating. Generally speaking, the surface roughness (Ra value) of metal after sandblasting can vary between 0.8-6.3 μ m depending on the abrasive particle size and spraying parameters.

Obtain specific surface textures

By selecting different parameters such as abrasive particle size, spray pressure, and angle, various specific textures can be obtained on metal surfaces. For example, using larger grit abrasives and lower jet pressure can produce noticeable and regular textures on metal surfaces, which can be used for decorative purposes. In the field of architectural decoration, after sandblasting the surface of stainless steel plates, a frosted effect can be obtained, which can be used to make elevator car interiors, building facade decorations, etc., increasing aesthetics.

3、 Improve the surface properties of metals

Improve fatigue strength

After sandblasting treatment, the compressive stress layer formed on the surface of the metal can improve its fatigue strength. During the process of abrasive impact on metal surfaces, the surface will undergo certain plastic deformation, which will result in residual compressive stress on the surface. For example, metal components in the aerospace field, such as the connectors of aircraft wings, have improved fatigue strength after sandblasting treatment, which can better withstand alternating loads and reduce the risk of component damage caused by fatigue.

Enhance corrosion resistance

On the one hand, sandblasting removes corrosion sources such as rust and oxide scale on the metal surface; On the other hand, appropriate surface roughness and clean surfaces are beneficial for forming uniform and dense protective films (such as coatings). For example, on the metal shell of a ship, sandblasting treatment followed by the application of anti-corrosion coating can improve the adhesion of the coating, effectively isolate the metal from contact with corrosive media such as seawater, and enhance the corrosion resistance of the metal.

The process flow of sandblasting includes material selection, sandblasting equipment, sand selection, processing parameters, testing, and other steps. Firstly, suitable materials should be selected for processing, and different sandblasting equipment and sand particles should be chosen according to the specific requirements and surface characteristics of the workpiece. Then determine the processing parameters based on the material and requirements of the workpiece, including sandblasting pressure, sandblasting distance, sand particle size, sandblasting time, etc. Afterwards, sandblasting processing will be carried out, and quality inspection and surface treatment will be carried out after the processing is completed.

Jet pressure is a key parameter that affects the sandblasting effect. Excessive pressure can cause the abrasive to excessively impact the surface of the workpiece, which may cause deformation and damage to the workpiece. At the same time, the breakage rate of the abrasive will also increase, affecting the uniformity of particle size. If the pressure is too low, it cannot effectively remove impurities from the surface of the workpiece or achieve the expected roughness. Different workpiece materials and abrasive types require different jet pressures. For example, for metal workpieces with high hardness (such as stainless steel), when using corundum sand abrasive, the spray pressure can be controlled at 0.4-0.6MPa; For softer materials such as aluminum, the pressure should be appropriately reduced, generally between 0.2-0.4 MPa.