Metal polishing

At present, the commonly used polishing methods are as follows:

1、Mechanical polishing
Mechanical polishing is a polishing method to obtain a smooth surface by cutting and plastic deformation of the surface of the material to remove the polished convex part. Generally, oilstone strips, wool wheels, sandpaper, etc. are used, mainly by manual operation. For special parts such as the surface of the rotary body, auxiliary tools such as turntables can be used, and the method of ultra-fine polishing can be used for high surface quality requirements. Super-finishing polishing is the use of special grinding tools, containing abrasive polishing fluid, tightly pressed on the workpiece is processed surface, for high-speed rotation. The use of this technology can be achievedThe surface roughness of Ra0.008um is the highest among various polishing methods. Optical lens molds often use this method.

2,chemical polishing

Chemical polishing is to make the material in the chemical medium surface micro convex part of the concave part of the preferential dissolution, so as to get a smooth surface, the main advantage of this method is that it does not require complex equipment, can be polished complex shape of the workpiece, can be polished at the same time a lot of workpiece, high efficiency. The core problem of chemical polishing is the preparation of polishing solution. 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, that is, by selectively dissolving the small protruding parts of 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. (2) Micro leveling: anodic polarization, surface brightness is improved.

4,ultrasonic polishing

The workpiece is placed in the abrasive suspension and placed together in the ultrasonic field, relying on the ultrasonic oscillation, so that the abrasive grinding and polishing on the surface of the workpiece. Ultrasonic machining macro force is small, will not cause deformation of the workpiece, but tooling production and installation is difficult. Ultrasonic machining 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 wave in the liquid can also inhibit the corrosion process and is conducive to the surface brightening.

5、Fluid polishing

Fluid polishing is to rely on high-speed flow of liquid and abrasive particles; scour the surface of the workpiece to achieve the purpose of polishing. Commonly used methods are: abrasive jet processing, liquid jet processing, fluid power grinding. Fluid power grinding is driven by hydraulic pressure, so that the liquid medium carrying abrasive particles flows through the surface of the workpiece at high speed. The medium is mainly made of a special compound with good flowability at a lower pressure and mixed with abrasive, and the abrasive can be made of silicon carbide powder.

6、magnetic abrasive polishing

Magnetic grinding and polishing is the use of magnetic abrasive under the action of a magnetic field to form an abrasive brush 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 reachRa0.1um。