Several ways to achieve mirror processing!

Mirror processing creates a surface that reflects images like a mirror, ensuring excellent surface quality. It enhances product aesthetics, reduces notch effects, and extends fatigue life, which is crucial for assembly and sealing structures. The main goal is to reduce surface roughness. Common polishing methods vary based on specific needs and can be selected accordingly for metal workpieces.

1. Mechanical polishing Mechanical polishing is a polishing method that relies on cutting and plastic deformation of the material surface to remove the convex parts after polishing to obtain a smooth surface. Generally, oil stone strips, wool wheels, sandpaper, etc. are used, and manual operation is the main method. Special parts such as the surface of a rotating body can use auxiliary tools such as a turntable. For high surface quality requirements, super-fine grinding and polishing can be used. Super-fine grinding and polishing uses a special grinding tool, which is pressed tightly on the surface of the workpiece in a grinding and polishing liquid containing abrasives and rotates at high speed. Using this technology, a surface roughness of Ra0.008μm can be achieved, which is the highest among various polishing methods. Optical lens molds often use this method.

2. Chemical polishing Chemical polishing is to make the microscopic convex parts of the material surface in the chemical medium dissolve preferentially compared with the concave parts, thereby obtaining a smooth surface. The main advantages of this method are that it does not require complex equipment, can polish workpieces with complex shapes, can polish many workpieces at the same time, and has high efficiency. The core issue of chemical polishing is the preparation of the polishing liquid. The surface roughness obtained by chemical polishing is generally several 10μm.

3. Electrolytic polishing The basic principle of electrolytic polishing is the same as that of chemical polishing, that is, it relies on selective dissolution of the tiny protrusions on the surface of the material to make the surface smooth. Compared with chemical polishing, it can eliminate the influence of the cathode reaction and has a better effect. 

4. Hawkingen mirror processing equipment, as a new polishing process, has unique advantages in the processing of many types of metal parts. It can replace traditional grinding machines, rolling, boring, honing, polishing machines, sanding machines and other metal surface finishing processing equipment and processes; making it easy to process metal workpieces with high finish. Hawker can not only polish, but also bring many additional benefits: it can improve the surface finish of the workpiece by more than 3 levels (the roughness Ra value can easily reach below 0.2); and the surface microhardness of the workpiece is increased by more than 20%; and the surface wear resistance and corrosion resistance of the workpiece are greatly improved. Hawker can be used to process various stainless steel and other metal workpieces.

5. Ultrasonic polishing Put the workpiece into the abrasive suspension and place it in the ultrasonic field together. Relying on the oscillation of the ultrasonic wave, the abrasive is ground and polished on the surface of the workpiece. Ultrasonic processing has a small macroscopic force and will not cause deformation of the workpiece, but the tooling is difficult to make and install. 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 to separate the dissolved products on the surface of the workpiece, and the corrosion or electrolyte near the surface is uniform; the cavitation effect of ultrasonic waves in the liquid can also inhibit the corrosion process and facilitate surface brightening.

6. Fluid polishing Fluid polishing relies on high-speed flowing liquid and the abrasive particles it carries to flush the surface of the workpiece to achieve the purpose of polishing. Common methods include: abrasive jet processing, liquid jet processing, fluid power grinding, etc. Fluid power grinding is driven by hydraulic pressure, so that the liquid medium carrying abrasive particles flows back and forth at high speed over the surface of the workpiece. The medium is mainly made of special compounds (polymer-like substances) with good flowability under low pressure and mixed with abrasives. The abrasive can be made of silicon carbide powder.

7. Mirror polishing Mirror, magnetic grinding and polishing Magnetic grinding and polishing is to use 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 to control processing conditions, and good working conditions. With suitable abrasives, the surface roughness can reach Ra0.1μm. The polishing mentioned in plastic mold processing is very different from the surface polishing required in other industries. Strictly speaking, 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 generally only requires a bright surface. The standards for mirror processing are divided into four levels: AO=Ra0.008μm, A1=Ra0.016μm, A3=Ra0.032μm, A4=Ra0.063μm. Since it is difficult to accurately control the geometric accuracy of parts by methods such as electrolytic polishing and fluid polishing, and the surface quality of methods such as chemical polishing, ultrasonic polishing, and magnetic grinding polishing does not meet the requirements, the mirror processing of precision molds is still mainly mechanical polishing.