Committed to providing customers with one-stop surface treatment solutions
To become the excellent surface treatment supplier in the globe
+86-13600510559
Phone
+86-13584969897
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: 37 Author: Site Editor Publish Time: 2022-07-14 Origin: Site
The surface friction coefficient of vacuum PVD coating is small, the surface friction coefficient of metal material to steel after surface polishing is generally around 0.9, the friction coefficient of vacuum PVD coating to steel is between 0.01 and 0.6, the friction coefficient of vacuum PVD coating material (AlCrN, AlTiN) commonly used in die-casting moulds is generally 0.4-0.6, the low friction coefficient makes The low coefficient of friction makes the surface friction of the vacuum PVD coated moulds lower during processing and the surface friction of the parts to be processed, and the surface quality of the parts is better than the parts produced by the moulds without coating.
The production conditions of die casting moulds are the most demanding, with metal solutions at high temperatures of 600-800°C, injection through high pressures and constant thermal expansion and contraction of the mould surface, resulting in a very short service life for die casting moulds, which constantly require mould repair and maintenance during production. The main causes of die casting mould failure are cracking, erosion, sticky material and deformation.
As the mould cavities work at high temperatures, the improved performance of die-casting moulds needs to have the following characteristics during the life of the mould, the accuracy and deformation of the cavity surface must be maintained under alternating high and low temperature conditions. Therefore die-casting mould material should have the characteristics of plastic mould, but also should have excellent high temperature resistance, hardness, oxidation resistance, tempering stability and impact toughness, with good thermal conductivity and fatigue resistance, the traditional die-casting mould using quenching, tempering, polishing process, the hardness of the material itself to improve limited, while the temperature due to the working temperature close to or more than tempering temperature, easy to caused by the mold's second tempering caused by mold hardness reduction and, mold deformation.
Vacuum PVD coatings can solve some of the problems encountered with die casting moulds by depositing a coating on the surface of the mould. The distinctive feature of this type of coating is its high thickness and high temperature resistance. Common die casting mould coatings include TiAlN, AlCrN and AlTiCrN. The common idea is to use a hard vacuum PVD coating to resist the high temperatures and impact of metallic fluids on the die.
All of the above coatings have a good resistance to high temperatures and a coefficient of friction against steel of less than 0.5, which can effectively solve the deformation caused by sticky materials and sudden cold and heat. At the same time, the hardness of several coatings is higher than HV3000, and can effectively maintain the hardness at high temperatures, which can resist the stress deformation caused by high temperature metal liquid on the mould.
Some coating companies have developed new technologies for the pre-treatment of vacuum PVD coatings in response to this problem, combining other surface technologies with vacuum PVD coatings to achieve some success in improving liquid metal sticking to the mould and thermal cracking. For example, HCVAC has developed a device that can complete the nitrocarburising of die casting moulds at the same time + vacuum PVD coating, effectively solving the problem of poor bonding between the traditional coating and the nitrided substrate, further improving the service life of die casting moulds. Most companies use the thick coating concept to improve the service life of the die by depositing a sufficient thickness of coating.
