Three common polishing methods for precision stamping dies

There are two main purposes for polishing precision stamping dies. One is to increase the brightness and beauty of the precision dies. The second is to make the mold easy to demold. When polishing, generally use a coarse whetstone to roughen the surface of the machined mold cavity, and then grind away the marks of the machine tool, and then use a fine whetstone to remove the coarse whetstone to achieve the mark, and then use the fine Sandpaper grinds the surface polished by fine whetstones, and finally uses polishing paste or abrasive paste to finish the surface of the cavity of the mold, and finally achieves a mirror-like effect.

1. Mechanical polishing: The mechanical polishing of precision stamping dies is a polishing method that obtains a smooth surface by cutting and plastic deformation of the material surface to remove the polished convex parts. Generally, whetstone strips, wool wheels, sandpaper, etc. are used, mainly by manual operation. For special parts such as the surface of the revolving body, auxiliary tools such as a turntable can be used. If the surface quality is high, the super-precision polishing method can be used. Super-precision grinding and polishing is the use of special grinding tools, in the grinding and polishing liquid containing abrasives, tightly pressed on the surface of the workpiece to be processed for high-speed rotation. Using this technology can achieve a surface roughness of Ra0.008μm, which is a prohibited word in various polishing methods. Optical lens molds often use this method.

2. Electrolytic polishing: Electrolytic polishing of precision stamping molds, that is, by selectively dissolving tiny protruding parts on the surface of the material to make the surface smooth. Compared with chemical polishing, the effect of cathode reaction can be eliminated, and the effect is better. The electrochemical polishing process is divided into two steps: (1) Macro leveling, the dissolved product diffuses into the electrolyte, and the geometric roughness of the material surface decreases by Ra>1μm. (2) Low light leveling, anode polarization, surface brightness increase Ra<1μm.

3. Ultrasonic polishing: The precision stamping die workpieces are put into the abrasive suspension and placed in the ultrasonic field together, relying on the oscillating action of ultrasonic waves to make the abrasive grinding and polishing on the surface of the workpiece. Ultrasonic processing has a small macro force and will not cause deformation of the workpiece, but tooling is difficult to manufacture and install.