Unlocking the Potential of 3D-Printed Polymers in Aerospace and Defense
In 2014, Airbus made history when it introduced a small metal bracket through additive manufacturing (AM) to secure an engine on one of its commercial jetliners. This milestone marked the beginning of an era of innovation in aerospace, pushing the boundaries of technology. The journey from that first AM experiment to today’s transformative landscape in the aerospace and defense industries has been nothing short of remarkable. The capabilities of AM have redefined the sector, offering unprecedented efficiencies and reshaping how we understand and approach manufacturing.
Aerospace and defense has emerged as a trailblazer in the adoption of AM. While aerospace and defense AM demand was negatively impacted during the COVID-19 pandemic, the global aerospace and defense additive manufacturing market is projected to grow from $3.73 billion in 2021 to $13.01 billion in 2028.
The surge in AM adoption within the aerospace and defense sectors owes much of its success to innovative advancements in materials. A diverse range of materials, including high-temperature AM polymers and composites, has ushered in new possibilities, enabling the rapid production of flight-worthy parts capable of withstanding extreme conditions, meeting strict industry standards for reliability, repeatability, and performance.
Why Replace Metal with High-Strength 3D-Printed Plastics?
High-strength 3D-printed plastics have emerged as alternatives to traditional metals in aerospace and defense applications. Materials such as reinforced nylon, PEEK, PEKK, PEI, and PPS now have mechanical properties rivaling certain metals, rendering them effective replacements in various contexts. These materials have impressive strength to weight ratios, enabling weight reduction and enhanced efficiency. Moreover, high-strength 3D-printed plastics offer superior corrosion resistance, chemical compatibility, and electrical insulation properties, making them advantageous in diverse industries. In aerospace and defense, all parts are classified into class A, B, and C with further subcategories, where all are given the classification based on their criticality for the flight operation. Traditionally, all, if not most, were made out of metals, but all of the class C parts could be manufactured with polymers if they pass some stringiest requirements, and the above-mentioned polymers do that.
Further, flying a part is the pinnacle within aerospace and defense, but volume is not in class A or class B parts; the volume and most of the maintenance are in class C parts and ground maintenance and support systems. High-performance polymers with AM hugely benefit these applications by speeding up the process, lowering the cost, and getting more flights operation-ready faster.
One example is PPS-CF as the primary tooling material for various molding processes. It can be a lightweight substitute for metal tools, especially in applications requiring corrosion and chemical resistance. Additionally, high-strength 3D-printed plastics have proven their mettle in sub-zero environments. For instance, new materials can withstand temperatures as low as -60 °C, making them ideal for replacing metal components in cold-weather applications.
Furthermore, high-strength 3D-printed plastics excel in high-impact scenarios, offering substantial advantages over traditional materials. They provide dimensional stability and durability, even after accidental drops or impacts. Utilizing these materials can significantly reduce the weight of tools and production aids compared to their metal counterparts.
In addition to these strengths, high-strength 3D-printed plastics offer design freedom, enabling the production of complex geometries that are often challenging to achieve with metal parts. This allows for part consolidation, optimization, enhanced performance, and reduced assembly time. The speed of 3D printing facilitates faster prototyping, production cycles, iterations, and shorter time to market.
Addressing Misconceptions About 3D-Printed Plastics
Despite the capabilities of high-strength 3D-printed plastics, there are common misconceptions about their feasibility as alternatives to metals in aerospace and defense applications.
One prevalent misconception is that polymers lack the strength and durability required for demanding applications. However, advancements in high-strength 3D-printed polymers have effectively closed the performance gap between plastics and certain metals. These materials now offer mechanical properties that meet or exceed stringent performance requirements.
Another misperception revolves around the suitability of plastics in high-temperature environments. While it’s true that some plastics have limitations in extreme temperatures, there are high-temperature polymers available that can withstand challenging thermal conditions, making them viable alternatives to metals and low-temperature materials that can withstand extreme cold temperatures.
The aerospace and defense industries have access to high-impact, high-temperature thermoplastic materials. These high-performance materials empower manufacturers to rapidly produce end parts that meet industry reliability, repeatability, and performance standards. Our new materials offer impact resistance five times that of PEI 9085 while remaining cost competitive. The material can withstand temperatures of up to 150 °C, is resistant to flame, smoke, and toxicity (FST), and has passed FAR 25.853 FST testing.
Another false belief is that plastics cannot achieve the desired aesthetic finishes. The latest generation of plastics is highly amenable to post-processing techniques and can be painted or treated to achieve the desired visual appearance.
Lastly, there’s a perception that plastic parts are less reliable or prone to failure. However, with proper design and manufacturing, high-strength 3D-printed plastics can provide exceptional reliability and durability, meeting stringent performance requirements.
Navigating the Transition
Transitioning from traditional metals to high-strength 3D-printed plastics presents specific challenges and tradeoffs that organizations must consider. Selecting the most suitable material for a particular application is a critical challenge. While high-strength 3D-printed polymers can match or exceed the mechanical properties of certain metals, it’s essential to assess factors like temperature resistance, chemical compatibility, and long-term durability to ensure the material can withstand the intended operating conditions.
The design and manufacturing process is another consideration. Designing for AM may require a different approach compared to traditional manufacturing methods. Leveraging the design freedom provided by 3D printing can optimize part performance, but it necessitates expertise in additive manufacturing principles. Designing for Additive Manufacturing (DFAM) knowledge allows for even lighter and more functional parts that can last longer just like the traditional parts. Collaborating with experienced partners specializing in high-strength 3D-printed polymers can mitigate these challenges. Such partners should offer comprehensive support, including material selection guidance, design optimization, and expertise in additive manufacturing processes. They can ensure a smooth transition and successfully implement 3D-printed plastics as metal alternatives.
A Path to the Future
As we look ahead, it’s evident that the aerospace and defense industries are at the forefront of leveraging the potential of additive manufacturing. They are the main reason for the advent of high-performance polymers in AM. The progress in high-strength 3D-printed polymers, advanced materials, and innovative processes has paved the way for a promising future. High-strength 3D-printed plastics are emerging as robust alternatives to traditional metals, offering performance, reliability, and design freedom.
In this exciting transformation journey, the aerospace and defense sectors set a precedent for other industries. From automotive to electronics, consumer goods, and biomedical applications, additive manufacturing offers a unique opportunity to rapidly produce parts on demand, reduce costs, minimize waste, and streamline supply chains. Well-informed and prepared, the best organizations will print their way to success in the digital age, seizing the full potential of high-strength 3D-printed plastics in an ever-evolving landscape of possibilities.
This article was written by Nirup Nagabandi, Ph.D., Vice President of Materials and Process Engineering, Essentium. For more information, visit here .