Common 6 kinds of mirror polishing process

Mirror polishing is currently a very important processing technology, next we will be divided into two articles to introduce the mirror polishing method and optical mirror polishing method. Let's look at the mirror finish first.

Mirror polishing is a kind of mirror processing technology, mainly through polishing to reduce the roughness of the surface of the workpiece, so that the surface of the workpiece can reflect the image like a mirror, so that not only has a high appearance level, but more importantly, can reduce the gap and extend the service life 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 methods of mirror polishing processing.

01, mechanical polishing

Mechanical polishing is by cutting, plastic deformation of the surface of the material to remove the polished convex and smooth surface polishing method, the general use of whitetstone strip, wool wheel, sandpaper, etc., mainly manual operation, special parts such as the surface of the rotary body, can use auxiliary tools such as rotary table, surface quality requirements can be used super polishing method.

Super finishing polishing is the use of special grinding tools, in the polishing liquid containing abrasive, tightly pressed on the workpiece to be machined surface, for high-speed rotation. Using this technology, the surface roughness Ra0.008μm can be achieved, which is the highest among various polishing methods, and this method is often used in optical lens molds.

02, chemical polishing

Chemical polishing is to dissolve the microscopic protruding part of the surface of the material in the chemical medium 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, can polish the workpiece with complex shape, and can polish 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 10μm.

03, electrolytic polishing

The basic principle of electrolytic polishing is the same as that of chemical polishing, that is, the surface is smooth by selectively dissolving small protruding parts on the surface of the material.

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) The macro leveling dissolved product diffused into the electrolyte, the geometric roughness of the material surface decreased, Ra>1μm.

(2) Low light level anodic polarization, surface brightness increased, Ra < 1μm.

04, ultrasonic polishing

The workpiece is put into the abrasive suspension and placed together in the ultrasonic field, and the abrasive is ground and polished on the workpiece surface by relying on the oscillation of the ultrasonic wave.

Ultrasonic processing macroscopic force is small, will not cause workpiece deformation, but 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, which is conducive to surface brightness.

05, fluid polishing

Fluid polishing relies on high-speed flowing liquid and the abrasive particles it carries to wash the surface of the workpiece to achieve the purpose of polishing. Common 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 through the surface of the workpiece at high speed.

The fluid medium is mainly made of special compounds (polymer-like substances) with good flow under low pressure and mixed with abrasives, which can be silicon carbide powder.

06, controlled flexible body certainty polishing

The controllable flexible body deterministic polishing technology is a new kind of mirror polishing technology, which aims to improve the controllability of optical machining and select flexible media which can adapt to the change of surface shape as polishing tool. This technology perfectly solves the bottleneck of modern optical parts processing, is the most high-end processing method of mirror polishing, and is also the trend of future industry development.

At present, the flexible media used in the controllable flexible body deterministic polishing technology mainly include magnetorheological polishing liquid and ion beam, and the corresponding polishing equipment is magnetorheological polishing machine and ion beam polishing machine.