Mechanical polishing：

Mechanical polishing is a polishing method that obtains a smooth surface by cutting and plastic deformation of the material to remove the polished convex parts. Generally, whetstone strips, wool wheels, sandpaper, etc. are used, and manual operation is the main method. Using auxiliary tools such as turntables, those with high appearance quality can adopt the method of super-finishing and polishing. Super-precision grinding and polishing is to adopt a special grinding tool, in the grinding and polishing liquid containing abrasives, it is pressed tightly on the surface of the workpiece to be processed for high-speed rotation. Using this technology, the surface roughness of Ra0.008μm can be reached, which is the highest among various polishing methods. Optical lens molds often use this method.

Chemical polishing：

Chemical polishing is to make the macroscopic convex part of the material preferentially dissolve in the chemical medium than the concave part, so as to obtain a smooth surface. The important advantage of this method is that it does not require complicated equipment, and can polish workpieces with complicated shapes, and can polish many workpieces at the same time, with high efficiency. The core problem of chemical polishing is the preparation of polishing solution. The surface roughness obtained by chemical polishing is generally several 10 μm.

Magnetic grinding and polishing：

At present, the main polishing methods for parts produced by the MIM process are magnetic grinding and mechanical polishing. After polishing, PVD treatment is generally required and can be made in different colors. The purpose is mainly to improve the appearance and decorative performance of the workpiece. It is more wear-resistant and corrosion-resistant to extend its service life; the most widely used field is consumer electronics.

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