Currently used polishing methods are there?
Polishing methods currently used are the following:
1 mechanical polishing
Mechanical polishing is by cutting and plastic deformation of the material surface is polished to remove the protrusions and get a smooth surface polishing method generally used Whetstone, wool wheel, sandpaper, mainly manual, special parts such as rotary surface, can be Use the turntable and other auxiliary tools, surface high quality requirements can be Superfinishing throw approach. Superfinishing is using a special abrasive polishing, the polishing liquid containing abrasive, and pressed against the surface of the workpiece to be machined, high speed rotary motion. Using this technology can achieve surface roughness Ra0.008 μ m, it is the highest in the various polishing methods. Optical lens mold often use this method.
2 Chemical polishing
Chemical polishing is to make the material in the chemical medium of some of the more convex surface microscopic concave part preferential dissolution, resulting in a smooth surface. The main advantage of this approach is that without complex equipment, the complex shape of the workpiece can be polished, can polish a lot of artifacts, and high efficiency. The core issue is the preparation of the polishing chemical polishing liquid. Chemical polishing the surface roughness was generally several 10 μ m.
3 Electropolishing
Electrolytic polishing and chemical polishing the same basic principles, namely the surface by selective dissolution of small projecting portion so that the surface is smooth. Compared with chemical polishing, it can eliminate the influence of cathodic reaction better. Electrochemical polishing process is divided into two steps:
(1) macro-leveling lysate diffusion to the electrolyte, a material decline rough surface geometry, Ra> 1 μ m.
(2) the dim light of formation of anodic polarization, the surface brightness increase, Ra < μ m.
4 ultrasonic polishing
The workpiece into the abrasive suspension and placed along the ultrasonic field, relying on the role of ultrasound oscillations, the abrasive grinding and polishing the surface of the workpiece. Ultrasonic machining macroscopic force is small, it does not cause deformation of the workpiece, but the tooling fabrication and installation more difficult. Ultrasonic machining can be combined with a chemical or electrochemical method. In solution corrosion, electrolysis basis, and then applying ultrasonic vibration stirring the solution, so that the surface lysate from near the surface corrosion or electrolyte uniform; ultrasonic cavitation in liquids are also capable of inhibiting the corrosion process, in favor of the bright surface.
5 hydrofinish
Hydrofinish rely on high-speed flow of liquid and carry abrasive scouring the surface to achieve the purpose of polishing. Common methods are: abrasive blasting, liquid jet machining, grinding fluid power. Fluid power is driven by a hydraulic grinding, abrasive carrying the liquid medium speed reciprocating flow through the workpiece surface. Mainly in the lower pressure medium flowing through good special compound (polymer-like substance) and mixed with the abrasive made of abrasive silicon carbide powder can be used.
6 Magnetic polishing
Magnetic abrasive polishing is formed by a magnetic abrasive brush in the magnetic field effect on the workpiece grinding. This method of high efficiency, good quality, easy to control the processing conditions, good working conditions. Using a suitable abrasive surface roughness may reach Ra0.1 μ m.
In the plastic mold in said polishing and surface finish required in other industries are very different, strictly speaking, should be called the mold of polished mirror finish. It is not only polishing their own high demands and the surface roughness, smoothness and geometric accuracy also has a high standard. Surface finish is generally only required to obtain a bright surface. Standard mirror finish is divided into four levels: AO = Ra0.008 μ m, A1 = Ra0.016 μ m, A3 = Ra0.032 μ m, A4 = Ra0.063 μ m, due to the electrolytic polishing, polishing method is very fluid difficult to precisely control the geometric accuracy and surface quality chemical polishing, ultrasonic polishing, grinding and polishing methods such as magnetic and meet the requirements, so the mirror processing precision molds or mechanical polishing based.