Common Mold Polishing Methods And Working Principle
In the mold manufacturing process, smooth processing and mirror processing after shape processing are called surface grinding and polishing of parts, which is an important process to improve the quality of the mold. Mastering a reasonable polishing method can improve mold quality and service life, thereby improving product quality.
Mechanical polishing is a polishing method that removes the convex surface of the surface of the workpiece by cutting or plastically deforming the surface of the material to obtain a smooth surface. Generally, oil stone strips, wool wheels, sandpaper, etc. are used, which are mainly manual operations, and the surface quality requirements are high. Super fine grinding method. Ultra-fine grinding and polishing is a special-purpose grinding tool. In the polishing liquid containing abrasive, it is pressed against the machined surface to perform high-speed rotary motion. With this technology, a surface roughness of Ra0.008 μm can be achieved, which is the best surface roughness in various polishing methods. This method is often used in optical lens molds. Mechanical polishing is the main method of mold polishing.
2. Chemical polishing
Chemical polishing is a process in which a material in a chemical medium causes a slightly convex portion of the surface to preferentially dissolve, thereby obtaining a smooth surface. The method can polish a workpiece with a complicated shape and can polish many workpieces at the same time with high efficiency. The surface roughness obtained by chemical polishing is generally Ra10 μm.
The basic principle of electropolishing is the same as chemical polishing, which is to selectively dissolve 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 good effect.
4. Ultrasonic polishing
Ultrasonic polishing is a processing method that uses a tool section for ultrasonic vibration to polish a brittle hard material through an abrasive suspension. The workpiece is placed in an abrasive suspension and placed together in an ultrasonic field, and the abrasive is ground and polished on the surface of the workpiece by the action of ultrasonic waves. Ultrasonic machining has a small macroscopic force and does not cause deformation of the workpiece, but it is difficult to manufacture and install the tooling.
5. Fluid polishing
Fluid polishing relies on flowing liquid and the abrasive particles it carries to wash the surface of the workpiece for polishing purposes. Hydrodynamic grinding is driven by hydraulics. The medium is mainly made of a special compound (polymeric substance) that flows at a lower pressure and is incorporated into an abrasive. The abrasive can be made of silicon carbide powder.
6. Magnetic grinding and polishing
Magnetic grinding and polishing is the use of magnetic abrasive to form an abrasive brush under the action of a magnetic field to grind the workpiece. This method has high processing efficiency, good quality and easy control of processing conditions. With a suitable abrasive, the surface roughness of the processing can reach Ra 0.1 μm.
7. Electric spark ultrasonic composite polishing
In order to improve the polishing speed of the workpiece with the surface roughness Ra of 1.6μm or more, the ultrasonic wave is combined with the special high-frequency narrow pulse high peak current pulse power supply for composite polishing, and the ultrasonic vibration and the electric pulse corrosion simultaneously act on the surface of the workpiece, and rapidly reduce The surface roughness, which is effective for polishing the rough surface of the mold after machining by car, milling, electric spark and wire cutting, is very effective.