DLC Coating Vacuum Plating

The DLC coating vacuum deposition production process generally includes three major steps: pre-DLC coating treatment, DLC coating, and post-DLC coating treatment.

Pre-DLC coating treatment is a prerequisite for obtaining a good coating. DLC coating generally includes steps such as mechanical processing, acid pickling, and degreasing. DLC coating mechanical processing refers to the use of mechanical methods to remove burrs, oxide layers, and other mechanical impurities from the surface of the plated part, making the surface smooth and clean. This ensures good adhesion between the DLC coating and the substrate, preventing the occurrence of burrs. The purpose of DLC coating acid pickling is to remove the oxide layer or other corrosion products from the surface of the plated part, while the purpose of DLC coating degreasing is to eliminate oils and fats from the substrate surface.

After pre-treatment, the DLC-coated parts can proceed to the DLC coating process. During DLC coating, attention must also be paid to the formulation of the DLC coating solution, the selection of current density, and the adjustment of temperature, among other factors. It should be noted that single-salt electrolytes are suitable for coatings with simple shapes and low appearance requirements, while complex salt electrolytes have high dispersion capabilities. During DLC coating, the current density and efficiency are low, making it mainly suitable for coatings with more complex surface shapes.

Vacuum Deposition Equipment DLC thin films have a wide range of deposition materials: They can deposit low-potential metals such as aluminum, titanium, and zirconium, which cannot be deposited by wet film methods. By introducing reactive gases and alloy targets, vacuum deposition machines can deposit coatings ranging from alloys to ceramics and even diamond. Moreover, the coating system can be designed according to specific needs. Compared to traditional water electroplating, it offers the following advantages:

Vacuum Deposition Equipment DLC thin films save metal materials: Due to the excellent adhesion, density, hardness, and corrosion resistance of vacuum coatings, the thickness of the deposited coating can be much thinner than that of conventional wet diamond-like carbon (DLC) film coatings, achieving the goal of material conservation. DLC thin films in vacuum deposition machines cause no environmental pollution: Since all coating materials are deposited on the workpiece surface through plasma in a vacuum environment, there is no solution pollution, making it environmentally harmless.

Traditional water electroplating has been restricted by the state and local governments due to its environmental pollution and the need to use highly toxic raw materials. Currently, some enterprises have established water electroplating industrial parks with centralized wastewater treatment, which has somewhat mitigated the issue of uncontrolled wastewater discharge. However, wastewater treatment is costly, energy-intensive, and leads to the waste of water resources. Additionally, countries like the EU have strict restrictions on the content of hexavalent chromium and nickel in imported products. The advantages of DLC thin films in vacuum deposition machines over traditional water electroplating make the gradual replacement of traditional water electroplating with vacuum deposition technology a viable path for technological upgrading and transformation in the traditional water electroplating industry. This not only aligns with national environmental policies but also meets the requirements for product exports while increasing the added value of exported products.

Characteristics of DLC Coatings:

Due to its diamond-like carbon composition, DLC possesses many excellent properties: high hardness—60 GPa or above Hv4800; low friction coefficient of 0.02; excellent film density; good chemical stability; and favorable optical properties, among others. The special performance of DLC coatings applied to molds far exceeds that of other hard coatings. DLC-coated stamping molds are primarily used in applications such as graphite cutting, cutting of various non-ferrous metals (e.g., aluminum alloys, copper alloys), and cutting of non-metallic hard materials (e.g., acrylic, fiberglass, PCB materials).
The industrial production of DLC coatings began in the late 20th and early 21st centuries. Compared to common hard coatings applied to molds (such as TiN, TiAlN, CrN, TiCN, etc.), it is a relatively new coating technology. Currently, there are very few manufacturers worldwide that can effectively apply this technology. DLC is a typical representative and development direction of the new generation of hard coating technologies and applications.