1. The purpose of mechanical pretreatment
Provide good appearance conditions, improve the quality of surface finishing;
Improve product grade;
Reduce the impact of welding;
Produce decorative effect;
Get clean surface.
2. Common methods of mechanical pretreatment
Commonly used mechanical pretreatment methods are polishing, sandblasting, brushing, rolling and other methods. The specific pretreatment is based on the type of product, the method of production, the initial state of the surface and the final finishing level. The Surface Thermometer is useful.
3. Principle and function of mechanical polishing
The friction of high-speed polishing wheel and workpiece produce high temperature result in plastic deformation of the metal surface, which flatten the convex and concave of metal surface, while the thin oxide film generated on the metal surface around the atmospheric oxidation become more and more bright after repeatedly grinding. The main role is to remove the burr, scratches, corrosion spots, trachoma, porosity and other surface defects on the surface of the workpiece. At the same time, remove the uneven on fine surface of the workpiece further to has a higher gloss until the mirror effect.
4. Principle and function of sandblasting
Spraying dry sand or other abrasive particles to the surface of aluminum products with the purified compressed air so as to remove the surface defects, showing a uniform matte sand. Main function: to remove the burrs, casting slag, other defects and dirt on the surface of workpiece; to improve the mechanical properties of the alloy; to achieve a uniform surface extinction effect.
5. The principle and role of brush
Brush is to scrub the burr, dirt and other dirty on the product surface with the help of the rotating brush. Treat aluminum alloy with wire drawing achieve the role of decoration.
6. Principle and role of rolling
Put the workpiece into the drum containing abrasive and chemical solution, so that the friction of workpiece and the abrasive, the workpiece and the workpiece make them polishing with the rotation of the roller.