Selective Laser Sintering (SLS) 3D printing is a viable solution for producing intricate and high-performance components across various industries.
But can SLS 3D printing meet aerospace industry standards? Aerospace components must adhere to strict standards for reliability, safety, material properties, and performance. As we’ll learn throughout this guide, SLS is revolutionising aerospace manufacturing and quickly becoming the aerospace industry’s go-to manufacturing method for a host of parts.
What is SLS 3D Printing?
SLS (Selective Laser Sintering) is an additive manufacturing technique that uses a high-powered laser to sinter powdered materials, typically nylon but also metal, or composite materials, into solid structures. The ability to create complex, lightweight geometries without the need for the expensive tooling needed in traditional manufacturing methods has made SLS a popular choice in sectors such as automotive, medical devices, and the aerospace sector.
What distinguishes SLS from other 3D printing technologies is its ability to create functional, durable parts directly from CAD files. The parts often require little to no post-processing, which can speed up production time and reduce overall manufacturing costs. These aren’t just prototypes either, 3D-printed engine components, air ducts and more are now being effectively used throughout the aerospace industry.
These lightweight components can have very intricate shapes that are not possible using traditional manufacturing processes, so additive manufacturing enables aerospace companies to design, create and install complex and efficient aerospace components into aircraft and spacecraft.
Aerospace Industry Standards: An Overview
The aerospace industry is governed by strict quality control and material standards due to the extreme conditions that parts must endure. Aerospace components are subject to high levels of stress and temperature fluctuations and must maintain mechanical integrity while remaining lightweight for fuel efficiency. Therefore, materials and processes must meet specific guidelines set by organisations like the Federal Aviation Administration (FAA), the European Union Aviation Safety Agency (EASA), and others.
Key aerospace standards relevant to 3D printing include:
1. Material Standards – AS9100 and ISO 9001 ensure the materials used in manufacturing meet durability, thermal resistance, and fatigue properties. Prototal are long-term holders of AS/EN 9100 and ISO 9001 quality certificates which means the parts produced by us always meet or surpass industry standards.
2. Mechanical Properties – Parts must retain their structural integrity under stress, meaning that material porosity, fatigue resistance, and tensile strength are critical factors. At Prototal we have a choice of materials for your parts and projects, including PEEK, Carbon PEEK, ULTEM, PP, ABS, PA2241 FR and Nylon 12. Need help choosing the right material for your part? Speak with our engineers today!
3. Certification for Flight Safety – Components need certification for airworthiness, a highly rigorous process that evaluates both the design and manufacturing processes.
4. Repeatability and Traceability – In aerospace, repeatable manufacturing processes and traceability are mandatory to ensure each part is identical and can be traced back to its source.
How Does SLS Align with These Standards?
1. Material Capabilities
One of the key advantages of SLS is the variety of high-performance materials it supports, including engineering-grade polymers like Nylon 11, Nylon 12, and thermoplastics reinforced with carbon fibre. For aerospace, materials must meet thermal and mechanical requirements.
The advanced materials mentioned above are ideal for producing the lightweight structures required for aerospace applications. Plus, SLS printing maintains material efficiency throughout the printing process – only ever using the correct amount of material for the structural elements – keeping the cost of complex geometries low and the structural integrity high.
This is something that traditional manufacturing techniques can not do. If it were possible to produce these complex geometries in a single part using traditional manufacturing methods, the material waste, time and cost wouldn’t be practical. In this way, additive manufacturing has revolutionised aerospace manufacturing.
2. Mechanical Performance
SLS components generally exhibit excellent mechanical properties like strength and fatigue resistance, especially for complex geometries that traditional manufacturing would struggle to produce. In aerospace, where weight reduction is crucial, SLS enables the production of lightweight, lattice-structured components, reducing fuel consumption and enhancing overall aircraft performance.
However, the challenge lies in ensuring parts are free of defects like porosity and inconsistencies in layer fusion, which can compromise the integrity of the component under stress. Prototal holds the aerospace EN 9100:2018 certification ensuring our parts are of the highest quality possible.
3. Certifications and Flight Safety
Certification for flight is perhaps the most formidable challenge for SLS parts. Aerospace authorities have stringent guidelines for part approval. This is where material choice is really important. SLS uses a wide variety of materials, each with its own strengths and weaknesses. If you’d like our help choosing the right material for your aerospace components, speak with our engineers today.
4. Repeatability
The repeatability of SLS printing remains a point of contention. Aerospace standards demand extremely low variance between parts. Any deviation can be critical in-flight components. Prototal’s innovations in powder quality, machine calibration, and real-time monitoring greatly improve the repeatability of SLS-produced parts.
Applications of SLS in Aerospace
SLS-printed parts are already being used in various aerospace applications, including:
1. Prototyping
SLS has been widely adopted for rapid prototyping in aerospace. Its ability to produce functional prototypes accelerates the design and testing phases. Nylon 12 is a great material choice for these parts. It’s a cost-effective material that will mimic the final part and is robust enough to withstand design and installation testing.
2. End-Use Parts
Once the design and testing phase is complete, the manufacturing process can begin with the ideal 3D printing material for your part. SLS polymers are currently being used in ducting, housings, and cabin interior components as well as much more. For instance, Airbus has integrated 3D-printed polymer parts in their A350 aircraft. With the right choice of material, the possibilities are nearly endless.
3. Spare Parts and On-Demand Manufacturing
The ability to produce parts on-demand without the need for expensive tooling is one of the key advantages of SLS for the aerospace industry. Aircraft operators can print spare parts quickly, reducing warehouse costs and downtime.
The Future of SLS in Aerospace
While SLS has not yet fully replaced traditional manufacturing for some aerospace components, its role is growing year after year – thanks to advancements in materials and printing technology. The ability to produce highly customised, lightweight parts at lower costs is driving innovation. Advancements in material science, better process control, and new certification frameworks mean that SLS is here to stay in the aerospace industry.
Conclusion
Selective Laser Sintering (SLS) 3D printing is helping to advance aerospace technology at a rapid pace. SLS excels in producing lightweight, complex geometries and has a host of applications in the aerospace industry and many other industries.
Aerospace engineering is forever changed by additive manufacturing and Prototal is at the forefront of this revolution. Whether you have a prototype or full-scale production part you need printing, get in touch. We have over 20 years at the forefront of our industry and been responsible for some of the largest advancements in 3D printing ever undertaken on British soil.