Crafting Tomorrow’s Surfaces: PVD Decorative Coatings Revolutionizing Industries
Decorative coating is a billion-dollar industry, and decorative coatings by physical vapour deposition, too.
Decorative coating industries encompass many sectors where coatings are applied to surfaces to enhance their appearance, protect against corrosion, improve durability, and provide various other functional benefits. Decorative coatings are used in industrial and commercial applications, including automotive, consumer electronics, jewellery, luxury watches, aerospace, and architectural building materials.
Decorative coatings serve functional and aesthetic purposes in the aerospace industry, as they are applied to aircraft interiors, seating, and cabin components. These coatings must be durable while maintaining a new appearance for an extended period. And Of course, PVD is the choice.
PVD COATINGS – Durability and corrosion resistance combined with aesthetic appeal
PVD stands for Physical Vapor Deposition, a process used to create decorative coatings on various surfaces, typically in automotive, electronics, aerospace, and other industries.
PVD coatings are known for their durability, corrosion resistance, and aesthetic appeal. Regarding decorative coatings using PVD, some typical applications and benefits include aesthetic enhancement, enhanced durability, corrosion resistance, customization, improved cleanliness and environmental friendliness.
PVD coating processes are generally more ecologically conducive than traditional plating methods because they produce fewer harmful byproducts and waste.
A variety of outstanding colours for decorative applications
PVD coatings can give surfaces a decorative and visually appealing finish. These coatings can create a wide range of colours, including gold, rose gold, black, and chrome-like finishes, making them famous for jewellery, watches, and consumer electronics.
PVD coatings provide a protective layer that enhances the durability of the underlying substrate. Such characteristics of PVD make the coatings suitable for applications where the coated surface may experience wear and tear, such as door handles, faucets, and other decorative hardware.
Improved corrosion resistance for applications in extreme environments
Also, it is critical to note that PVD coatings can improve the corrosion resistance of materials, which is crucial in outdoor and marine applications. Coated components can withstand exposure to moisture and harsh environmental conditions without corroding.
Customized coatings and fulfillment of specific individual requirements
PVD coatings can be customized to achieve specific decorative effects and colours. Manufacturers can control coating thickness and composition to meet aesthetic and functional requirements.
Some PVD coatings have a low-friction surface, making them easier to clean and maintain. This property is particularly beneficial in applications like kitchen appliances, where cleanliness is a priority. PVD coating processes are generally more environmentally friendly than traditional plating approaches because they produce fewer harmful byproducts and waste.
PVD TECHNOLOGY – the background
Standard PVD coating methods include sputter deposition and evaporation. These processes involve material deposition onto a substrate in a vacuum chamber, resulting in a thin, uniform coating with excellent adhesion properties. HIPIMS, or High-Power Impulse Magnetron Sputtering, is an advanced PVD-based thin-film deposition technique used in materials science and various industrial applications.
HiPIMS for thin films with unique properties
It is a variation of the more traditional magnetron sputtering process and is known for its ability to produce high-quality thin films with unique properties. HIPIMS is based on the sputtering method, which involves the removal of material from a target (usually a metal or metal alloy) and depositing it onto a substrate to form a thin film.
HiPIMS demonstrates its unique benefits for decorative coatings
In HIPIMS, the sputtering is achieved using high-power pulses of energy. After demonstrating success in various industries and applications, such as semiconductor manufacturing, optical coatings, cutting tools, and wear-resistant coatings, HiPIMS has now entered decorative coatings.
The ability of HiPIMS to deposit high-quality thin films with improved adhesion and performance makes it valuable in research, development, and production environments. Nearly a year ago, the control of target poisoning and subsequently controlling the colour of the final coating layer material by HiPIMS was demonstrated in industrial systems.
However, the seminal work for this technical concept of colour tuning by target poisoning in HiPIMS was first reported by Rajesh Ganesan and co-workers in their works (R Ganesan et al. 2016 J. Phys. D: Appl. Phys. 49, 245201 and R Ganesan et al. 2017 J. Appl. Phys. 121, 171909).
HiPIMS enables high level tuning of thin films
In both works, it has been demonstrated that competition between target erosion and compound layer formation during pulse cycles in reactive HiPIMS opens up the possibility
of tuning discharge conditions and the properties of deposited films by varying the duty cycle in situ without altering the reactive gas mixture.
Such effects can produce depositing layers of tunable colours and surface smoothness, which means HiPIMS can demonstrate the varying touch-and-feel impact on the same object; either you can have a smooth surface or a rough surface with precise definition and control, which is not possible by any other PVD or CVD techniques.
In other words, I have been advocating for over half a decade that HiPIMS can tune the colour coordinates L*, a* and b* independently, which can be dedicated purely to the target poisoning effect described by the research work of Ganesan et al. mentioned above.
L* indicates lightness, a* is the red/ green coordinate, and b* is the yellow/blue coordinate. Deltas for L* (ΔL*), a* (Δa*) and b* (Δb*) may be positive (+) or negative (-). However, the total difference, Delta E (ΔE*), is always positive.
Precise control over thin film thickness with HiPIMS
The pulsed nature of HIPIMS allows for precise control over film thickness, composition, and microstructure and thus can bring a defined colour in repeated experiments.
HiPIMS enable the process engineers to tailor the process parameters to meet specific requirements. In summary, decorative coatings using PVD offer a combination of aesthetics, durability, and functionality. They find applications in a wide range of industries where both visual appeal and protection are essential.
Note: The content is based on the article which was originally published in VERNICIATURA INDUSTRIALE_666_10•2023, authored by Christos Pernagidis, CEO of Avaluxe