The surface of 3D printing is sometimes rough, for a better surface effect, we need to do polishing.
Polishing refers to the use of mechanical, chemical or electrochemical action to reduce the surface roughness of the workpiece to obtain a bright and smooth surface.
Polishing does not improve the dimensional accuracy or geometric shape accuracy of the workpiece, but for the purpose of obtaining a smooth surface or mirror gloss, and sometimes to eliminate gloss (matting).
Let's look at 6 polishing methods
01. Mechanical polishing
Mechanical polishing is a polishing method that removes the polished convex part by cutting and plastic deformation of the material surface to obtain a smooth surface. Generally, oil stone strips, wool wheels, sandpaper, etc. are used.
The method of fine grinding and throwing.
Ultra-fine polishing uses a special abrasive tool, which is pressed against the surface of the workpiece to be processed in a polishing liquid containing abrasives for high-speed rotation.
Optical lens molds often use this method.
02. Chemical polishing
Chemical polishing is to make the microscopic convex part of the surface of the material dissolve preferentially compared with the concave part in the chemical medium, so as to obtain a smooth surface.
The main advantage of this method is that it does not require complex equipment, can polish workpieces with complex shapes, and can polish many workpieces at the same time, with high efficiency.
The core problem of chemical polishing is the preparation of polishing fluid.
03. Electropolishing
The basic principle of electrolytic polishing is the same as that of chemical polishing, that is, to make the surface smooth by selectively dissolving the tiny protrusions on the surface of the material.
Compared with chemical polishing, it can eliminate the influence of cathode reaction, and the effect is better.
04. Ultrasonic polishing
Put the workpiece into the abrasive suspension and place them together in the ultrasonic field, relying on the oscillation of the ultrasonic wave, the abrasive is ground and polished on the surface of the workpiece.
05. Fluid polishing
Fluid polishing relies on high-speed flowing liquid and the abrasive particles it carries to scour the surface of the workpiece to achieve the purpose of polishing.
Commonly used methods are: abrasive jet processing, liquid jet processing, hydrodynamic grinding, etc.
Hydrodynamic grinding is driven by hydraulic pressure, so that the liquid medium carrying abrasive particles flows back and forth across the surface of the workpiece at high speed.
The medium is mainly made of a special compound with good flowability under relatively low pressure and mixed with abrasives.
The abrasives can be silicon carbide powder.
06. 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 control of processing conditions, and good working conditions.
