Thin film deposition is a process essential across a range of industries. This technology can alter the qualities of a target surface, enhancing durability, erosion resistance, electric conductivity, and performance. One unique application of thin film deposition is within aerospace.
Thin film deposition in the aerospace industry is useful for many materials that resist rust, erosion, radiation, dust, and other contaminants. Applying thin-film coatings to these materials can boast numerous advantages, and as such, aerospace has adopted thin-film deposition as a central process in materials production.
Read on to learn the function and applications of thin film deposition in aerospace.
What is Thin Film Deposition?
In short, thin film deposition is the process of creating and depositing a thin layer of material — between a few nanometres and 100 micrometres in thickness — onto substrates. This process forms individual thin film coatings, and the number of layers within the coatings can vary depending on the material.
The two main thin film deposition methods include physical and chemical vapor deposition, which we will discuss more below. Both methods depend on having a tight control environment to maintain the desired consistency, performance, and temperature.
The applications of thin film deposition are widespread, including valuable uses within the aerospace industry.
The Role of Thin Film Deposition in the Aerospace Industry
The thin film deposition applications within aerospace continue to expand. Today, aerospace companies utilise the many benefits of this process, explained below, within a wide range of devices, materials, and components. With time, the adoption of thin film deposition will become standard in even more processes.
While thin film deposition has many aerospace applications, this industry has also begun testing the development of thin films while in space [1]. Conducting thin-layer deposition in microgravity may allow for more precise layering on devices like artificial retinas, semiconductors, and sensors.
Still, more research is needed to determine the efficiency, durability, and performance of thin-film materials produced in microgravity.
Benefits of Thin Film Deposition in Aerospace Applications
Thin film deposition offers many benefits that make it suitable for aerospace applications, technologies, and components.
First, many thin films have high erosion resistance [2].
Traditional materials used within windows and windshields are susceptible to scratches, which can lead to limited performance, rust, and other malfunctions over time. Coating these materials in a thin layer of polysiloxane or another high-hardness material can amplify erosion resistance without altering the other benefits of the window material.
Another major benefit of thin-film technology in aerospace is its potential to enhance fuel efficiency.
Aircrafts must use the lightest materials possible to minimise fuel consumption. Fuel consumption contributes to many variables, such as carbon emissions, operating costs, worker safety, etc. But space manufacturers avoid sacrificing material weight for quality.
Utilising thin-film coatings can enable aircraft materials to provide the necessary durability and performance without adding unnecessary weight. Thin-film coatings are just a few atoms thick, and even dense metal components in these capacities are lightweight.
Finally, polymer-based coatings created with thin film deposition are typically less expensive and more convenient to manufacture. Aerospace organisations can benefit from cost savings when implementing these technologies instead of more expensive metal coatings or components.
Examples of Thin Film Deposition for Aerospace Components
The advantages above have allowed thin-film coatings to benefit many components in aerospace production, manufacturing, and maintenance. Today, you can see thin-film deposition present in the following components:
- Aeronautics systems
- Target designators
- Countermeasures
- Multispectral imaging sensors
- Window and windshield coating
- Aluminium surface materials
Types of Thin Film Deposition Techniques Used in the Aerospace Industry
The two main types of thin film deposition include physical vapour deposition (PVD) and chemical vapour deposition (CVD).
Understanding the differences between PVD and CVD (read more here: PVD vs. CVD) is essential to determine the proper systems within your applications. While neither technique produces superior results in every scenario, the suitable technique within each application depends on the target materials and functions of that usage [3].
PVD is a method of producing thin-film coatings with physical means as opposed to chemical ones. First, a laser or high-power electricity device gasifies a solid precursor material. The vaporised atoms are placed in a reacting chamber with the coating substrates. The source material sticks to the substrates, forming a thin coating on the surface.
Meanwhile, as the name suggests, CVD uses chemicals to produce the substrate coatings [4]. This process involves mixing a source material with a volatile precursor — usually a hydride or halide — to break down the source material.
The source material vapour is then transferred into a reaction chamber that contains a substrate. This process deposits reactants into the substrate, breaking down the precursor. A thin coating of the source material remains on the substrate.
One advantage of CVD over PVD is that it can create precise coatings on an uneven surface as well as a flat, smooth one. The properties of CVD make it extremely versatile. However, this chemical process can create volatile by-products that must be safely removed.
Final Thoughts
Thin film deposition is a feat of modern science that has benefitted many industries. With their erosion resistance, strength, cost-effectiveness, and other properties, thin-film coatings are ideal for numerous aerospace applications.
As an aerospace engineer, incorporating thin film deposition into your manufacturing and engineering processes can provide an excellent return on investment. Choosing the right system is essential to ensure that you optimise the benefits of your thin-film investment.
At Korvus Technology, we offer a wide range of thin film deposition systems, accessories, and components to suit your needs. Get in touch today to learn how this process can feature in your projects.
References
[1] In-space production applications: thin-layer deposition. ISS US National Laboratory. (n.d.). Retrieved December 28, 2022, from https://www.issnationallab.org/ispa-thin-layer-deposition/
[2] Ranade, A. N., & Matos, M. A. (2012). High performance thin films for aerospace applications. Research Gate. Retrieved December 28, 2022, from https://www.researchgate.net/publication/267901124_High_Performance_Thin_Films_for_Aerospace_Applications
[3] Stephen Ogbonna Mbam et al. (2019). Thin-film coating; historical evolution, conventional … IOPScience. . Retrieved December 28, 2022, from https://iopscience.iop.org/article/10.1088/2053-1591/ab52cd[4] Chemical Vapor Deposition. (2008). The Materials Science of Semiconductors. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-68650-9_12
