As a new polishing process, plasma polishing is a trend in stainless steel polishing. If we can make good use of plasma polishing will save us a lot of time and costs.
PVD and CVD are the most commonly used surface treatment methods for tools and moulds, CVD is based on chemical vapour deposition and PVD is based on physical vapour deposition, as they differ in principle, the final coating results are different and each has its own focus in application.
Electrolytic polishing has great advantages over traditional polishing, low cost, small footprint, can polish complex workpieces, has unmatched advantages over traditional polishing.
PVD stands for Physical Vapour Deposition. PVD coating refers to a thin film deposition technique whereby solid materials are sputtered or evaporated in a vacuum environment and deposited as pure materials or alloy components to form a coating on a substrate.
There are many different types of ion sources used in vacuum coating. The main ones are: high frequency ion sources, arc discharge ion sources, Kaufmann ion sources, radio frequency ion sources, Hall ion sources, cold cathode ion sources, electron cyclotron ion sources, anode layer ion sources, inductively coupled ion sources and probably many other types of ion sources that have not been mentioned.
Views: 32 Author: Site Editor Publish Time: 2022-08-01 Origin: Site
PVD coating is a common tool coating used in industrial production and has been developed for a long time, and is widely used in cutting tools, tooling and other finishing industries. However, as the level of industrial production increases, the requirements for tool coatings are becoming higher and higher. Although the preparation methods are progressing, it is inevitable that there will still be some shortcomings in the preparation process.
1、Large droplets
It is a typical drawback in the process of PVD coating preparation, when high-energy ions bombard the target material to obtain high stacking power conditions, the general three-dimensional scale of the particles is more uniform and greater than 1.5um, which is a coating drawback that seriously affects the machining accuracy of the tool and has an impact on the repeat positioning accuracy of the tool and the appearance quality of the machined parts.
2、Cumulus and flake projection
Is due to the vacuum chamber particles or particles on the exterior of the substrate in the coating stack once attached to the substrate exterior, following the stack exists in the coating, often more flimsy coating shortcomings, shortcomings of the area scale is often much larger than the height, in the use of easy to peel off.
3、Vacuum or disc-shaped pit
There are foreign particles in the PVD coating that are not firmly bonded with the coating that fall off spontaneously under the effect of high stress, constituting a vacancy; there is contamination between the substrate, which falls off due to the effect of thermal stress when cooling in the vacuum chamber and constitutes a disc-shaped pit or reveals the substrate shortcomings.
4、Pinhole or bubble
When there are narrow pits on the exterior of the substrate, the coating buildup process in the pits side priority growth, gradually constitute a coating pinhole shortcomings, and the appearance of polishing treatment, this shortcoming exterior a thin layer of coating is worn off, exposed. The bubbles are 100-400nm micro-particles, which are formed into flakes within the vacuum chamber, and when they pass through the plasma they are able to obtain an electrical charge, and this ion is able to reach the surface of the substrate, and is held in place under the effect of the electrical charge, forming a bubble-type defect during the build-up process.
1、Vacuum polishing place
The amount of gas released from the vacuum chamber as well as the internal components is directly related to the external surface area of the material. The atomic density of the solid surface is about 2×1019 m-2. Considering the unevenness of the surface, the practical solid surface will absorb a large number of gas molecules. By making the surface flatter through polishing, the external surface area can be reduced considerably, thus reducing the number of gas molecules adsorbed on the surface. The two main polishing techniques are glass shot blasting and electrolytic polishing.
2、Ultrasonic cleaning
Ultrasonic cleaning is the use of ultrasound in the liquid cavitation effect, acceleration effect and direct flow effect on the liquid and dirt direct, direct effect, so that the dirt layer is dissipated, emulsification, stripping and reach the cleaning intention. Into the liquid after the introduction of ultrasound, the intense movement of the liquid so that the local pressure difference. The low pressure part will occur a large number of bubbles, when the pressure rises from the beginning, these bubbles will break in an instant, so that shock waves occur in the liquid. The shock wave will strip the solid exterior of the oil. The liquid used for ultrasonic cleaning is usually alcohol or acetone. When the ultrasonically cleaned parts are placed in the atmosphere, the alcohol or acetone will immediately vaporise and will not leave scale on the surface of the parts.