Several ways of processing mirror surface of mechanical parts

Mirror processing refers to the processing surface can reflect the image like a mirror, this level has reached a very good workpiece surface quality, mirror processing can not only create a high "appearance level" for the product, but also reduce the notch effect, prolong the fatigue life of the workpiece; It is of great significance in many assembly and sealing structures. Polishing mirror processing technology is mainly used to reduce the surface roughness of the workpiece. When selecting the polishing process method for metal workpiece, different methods can be selected according to different needs. The following are several common polishing mirror processing methods.

1, Mechanical polishing

Mechanical cutting, polishing is to rely on material surface plastic deformation after removed by polishing the convex part of the smooth surface polishing method, commonly used article oil stone, wool wheel, abrasive paper, etc., with manual operation is given priority to, special components such as surface of solid of revolution, can use tools such as turntable, high surface quality can be used over lapping method. Super finishing polishing is the use of special grinding tools, containing abrasive polishing liquid, pressed on the workpiece is processed on the surface, for high-speed rotation movement. The surface roughness of Ra0.008μm can be achieved by using this technology, which is the highest among all polishing methods. This method is often used in optical lens molds.

2,Chemical polishing

Chemical polishing is to let the material in the chemical medium surface microcosmic convex part of the concave part preferentially dissolved, so as to obtain smooth surface. The main advantage of this method is that it does not need complex equipment, can polish complex shape workpiece, can simultaneously polish many workpiece, high efficiency. The core problem of chemical polishing is the preparation of polishing fluid. The surface roughness obtained by chemical polishing is generally 10μm.

3, Electrolytic polishing

The basic principle of electrolytic polishing is the same as that of chemical polishing, which is to make the surface smooth by selectively dissolving the tiny protruding part of the surface of the material. Compared with chemical polishing, the effect of cathode reaction can be eliminated. The electrochemical polishing process is divided into two steps :(1) macroscopic leveling solution diffuses into the electrolyte, and the material surface becomes rough and decreases with Ra>1μm. (2) Anodic polarization with low light level, surface brightness increased, Ra<1μm.

4, Haukeng mirror processing equipment

As a new polishing process, it has unique advantages in processing many kinds of metal parts. It can replace the traditional grinding machine, rolling, boring and rolling, honing, polishing machine, sand belt machine and other metal surface finishing equipment and technology; It makes it easy to process metal workpiece with high finish. Hawker can not only polish, but also bring many additional benefits: it can improve the surface finish of the processed workpiece by more than 3 grades (roughness Ra value can easily reach below 0.2); The surface microhardness of the workpiece is increased by more than 20%. And greatly improve the surface wear resistance and corrosion resistance of the workpiece. Hawker can be used to deal with all kinds of stainless steel and other metal workpiece.

5. Ultrasonic polishing

The workpiece is put into the abrasive suspension and placed together in the ultrasonic field, and the abrasive is grinded and polished on the workpiece surface by the oscillation of ultrasonic wave. Ultrasonic processing macro force is small, will not cause workpiece deformation, but the tooling production and installation is more difficult. 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; Ultrasonic cavitation in the liquid can also inhibit the corrosion process, conducive to surface lighting.

6. Fluid polishing

Fluid polishing relies on high-speed liquid and abrasive particles to wash the workpiece surface to achieve the purpose of polishing. The common methods are abrasive jet processing, liquid jet processing, fluid power grinding and so on. Hydrodynamic lapping is driven by hydraulic pressure to make the liquid medium carrying abrasive particles flow over the workpiece surface at high speed. The medium is mainly made of special compounds (polymer-like substances) with good flow ability under low pressure and mixed with abrasive, which can be made of silicon carbide powder.

7. Magnetic polishing

Magnetic abrasive polishing is the use of magnetic abrasive under the action of magnetic field formed abrasive brush, grinding workpiece. This method has high processing efficiency, good quality, easy control of processing conditions and good working conditions. The surface roughness can reach Ra0.1μm with proper abrasive. In the plastic mold processing said polishing and other industries required surface polishing is very different, strictly speaking, the mold polishing should be called mirror processing. It not only has high requirements for polishing itself but also has high standards for surface flatness, smoothness and geometric accuracy. Surface polishing is generally only required to obtain a bright surface. Mirror processing standards are divided into four levels :AO=Ra0.008μm, A1=Ra0.016μm, A3=Ra0.032μm, A4=Ra0.063μm, due to electrolytic polishing, fluid polishing and other methods it is difficult to accurately control the geometric accuracy of parts, The surface quality of chemical polishing, ultrasonic polishing, magnetic polishing and other methods can not meet the requirements, so the mirror processing of precision mold is mainly mechanical polishing.