1. Overview of Vacuum Coating Principles
Vacuum coating technology is a surface deposition technology based on Physical Vapor Deposition (PVD) or Chemical Vapor Deposition (CVD). Under high vacuum conditions, solid or gaseous coating materials are converted into free particles through heating, plasma bombardment, or chemical reactions, and are subsequently deposited onto the substrate surface to form a thin film.
Typical processes include:
Evaporation Coating (e.g., thermal resistance evaporation, electron beam evaporation),Magnetron Sputtering, Ion Plating, Chemical Vapor Deposition (CVD)
While process selection varies depending on the application, the ultimate goal remains consistent: achieving high adhesion, uniformity, and film stability.
2. Categories of Common Vacuum Coating Materials
According to film function and process requirements, vacuum coating materials are mainly classified into the following categories:
(1) Metal Materials
Aluminum (Al): Widely used for decorative coatings and reflective layers, such as in automotive reflector bowls and decorative panels.
Titanium (Ti): Applied in hard coatings or for producing blue and gold decorative films.
Chromium (Cr): A key PVD alternative to traditional electroplating, known for high brightness and corrosion resistance.
Stainless Steel (SUS304, SUS316, etc.): Used for metal-look coatings with enhanced wear resistance.
Copper (Cu), Silver (Ag), Gold (Au): Commonly used in electronic, decorative, and conductive functional coatings.
(2) Ceramic and Oxide Materials
Silicon Dioxide (SiO₂): Applied in anti-reflective (AR) coatings, optical enhancement layers, and insulating films.
Titanium Dioxide (TiO₂): A high-refractive-index material frequently used in optical interference coatings.
Zirconium Dioxide (ZrO₂): Offers excellent thermal stability and high wear resistance.
Aluminum Oxide (Al₂O₃): Known for high hardness, often used as a protective hard coating.
(3) Nitrides and Carbides
Titanium Nitride (TiN): A typical golden decorative coating material with superior hardness and corrosion resistance.
Chromium Nitride (CrN), Zirconium Nitride (ZrN): Widely used in tool coatings and wear-resistant applications.
Silicon Carbide (SiC), Titanium Carbide (TiC): Suitable for high-hardness and high-temperature-resistant applications.
3. Material Selection Criteria and Process Compatibility
The effectiveness of coating depends on both the deposition technique and the selected materials. Key factors to consider include:
Substrate Compatibility: Different substrates such as plastic, metal, and glass demand specific film adhesion properties.
Functional Requirements: Choose coating materials based on needs such as oxidation resistance, conductivity, or optical filtering.
Process Suitability: For example, magnetron sputtering is more compatible with metals and oxides, while evaporation is suitable for low-melting-point materials.
For instance:
In PVD-based decorative coatings for automotive interior components, Cr, Ti, and TiN are widely used as eco-friendly alternatives to electroplating.
In anti-reflective (AR) optical coatings, SiO₂ and TiO₂ form the fundamental material combination.
Material Selection Determines Film Quality
The performance of a vacuum-deposited film is not only influenced by equipment and process control but also critically by material choice. Selecting the right coating material and pairing it with the appropriate deposition technique is key to achieving optimal film functionality.
—This article was published by vacuum coating equipment manufacturer Zhenhua Vacuum
Post time: Jun-27-2025