What are the polishing methods for metal parts?

u200bCurrently commonly used metal parts polishing methods are as follows: 1. Mechanical polishing Mechanical polishing is a polishing method that relies on cutting and plastic deformation of the material surface to remove the polished convex parts to obtain a smooth surface. Generally, oil stone strips, wool wheels, Sandpaper, etc., are mainly operated by hand. For special parts such as the surface of the rotating body, auxiliary tools such as turntables can be used. For those with high surface quality, the method of ultra-precision polishing can be used. Ultra-precision polishing is the use of special abrasive tools, which are pressed against the processed surface of the workpiece in a polishing fluid containing abrasives for high-speed rotation. The surface roughness of Ra0.008um can be achieved by using this technology, which is the highest among various polishing methods. Optical lens molds often use this method. 2. Chemical polishing Chemical polishing is to make the surface microscopic convex part of the material in the chemical medium dissolve preferentially than the concave part, so as to obtain a smooth surface. The main advantage of this method is that it does not require complex equipment and can polish workpieces with complex shapes. Polishing many workpieces at the same time, with high efficiency. The core problem of chemical polishing is the preparation of polishing liquid. The surface roughness obtained by chemical polishing is generally several 10um. 3. Electrolytic polishing The basic principle of electrolytic polishing is the same as that of chemical polishing, namely by selectively dissolving tiny protrusions 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) Macroscopic leveling: the dissolved products diffuse into the electrolyte, and the geometric roughness of the material surface decreases. (2) Micro leveling: anodic polarization, the surface brightness is improved. 4. Ultrasonic polishing Put the workpiece into the abrasive suspension and put it in the ultrasonic field together, relying on the oscillation effect of the ultrasonic, so that the abrasive is ground and polished on the surface of the workpiece. Ultrasonic machining has a small macroscopic force and will not cause deformation of the workpiece, but it is difficult to manufacture and install tooling. Ultrasonic processing can be combined with chemical or electrochemical methods. On the basis of solution corrosion and electrolysis, ultrasonic vibration is applied to stir the solution, so that the dissolved products on the surface of the workpiece are separated, and the corrosion or electrolyte near the surface is uniform; the cavitation effect of ultrasonic in the liquid can also inhibit the corrosion process and facilitate surface brightening. 5. Fluid polishing Fluid polishing relies on high-speed flowing liquid and the abrasive particles it carries; scouring the surface of the workpiece to achieve the purpose of polishing. Commonly used methods are: abrasive jet processing, liquid jet processing, hydrodynamic grinding and so on. Hydrodynamic grinding is driven by hydraulic pressure to make the liquid medium carrying abrasive particles flow back and forth across the surface of the workpiece at high speed. The medium is mainly made of special compounds with better flowability under lower pressure and mixed with abrasives. The abrasives can be made of silicon carbide powder. 6. Magnetic Grinding and Polishing Magnetic grinding and polishing uses magnetic abrasives to form abrasive brushes under the action of a magnetic field to grind the workpiece. This method has high processing efficiency, good quality, easy control of processing conditions, and good workpiece conditions. Using suitable abrasives, the surface roughness can reach Ra0.1um.