Aerospace is one of the main industries embracing additive technologies, and the large growth in industrial metal 3D printing over the past few years can be largely attributed to the A&D industry.
Major players in the sector are accelerating the transition from prototyping to large-scale production as they accept the technology for in-house use, and service providers to the industry are helping to mature the process and shorten development cycles.
Additively “printed” metal parts are already in use in jet engines today!
Three criterion exist for additive manufacturing (AM) process technologies to be used effectively: they must be able to capitalize on the uniqueness the disruptive technology offers, they must provide functional parts that meet strict specifications and finally, they must be repeatable. This is true regardless of industry, but A&D is currently the driving force of additive in the industrial market.
Known for opening up design freedom, AM allows the aerospace sector to take full advantage of these possibilities and remove barriers that traditional manufacturing processes had created. Companies are learning how to design with a new independence from complexity; rather than choosing a geometry for a component, AM users can determine the specs required and then derive the geometry, leading to more efficiently built and lighter parts.
We work directly with Sintavia, a service provider of AM expertise specifically for the A&D sector, and see how they assist companies with optimizing designs to both lightweight components and improve performance.
Topology optimization is key to making sure you exploit the advantages of AM and taking the requirements of a cooling manifold bracket, for example, Sintavia was able to present five design variations to be tested for tensile strength, fatigue and metallurgical properties.
With the ability to print multiple prototypes in one process, these varying designs can also be tested faster. In the example of the manifold brackets, the original design and all variations were printed on one plate of an SLM 280HL with twin 400-W lasers in a single, 24-hour build. This ability to prototype faster significantly reduces the design and development cycle.
Qualification, however, continues to be one of the largest hurdles to expansion of AM. The rate of adoption is still slow, creating a bottleneck where a huge number of parts that could be made additively exist, but very little actually makes it to production as certifications struggle to keep up with individual component, machine and process qualifications.
Yet this knowledge base is growing—Sintavia knows parts manufactured by AM are subjected to dimensional, material and mechanical verification testing. With metallurgical lab services, Sintavia runs impact, hardness and both tensile strength and fatigue testing at elevated temperatures, specifically aimed at shortening time to market. They are a part of a new supply chain being created for these new processes, and in the grander picture of additive manufacturing overall, in the pursuit of completely new business models not previously possible without AM.
Yet these prototypes are not just components built for testing—once approved they must still be manufactured additively, as there is simply no other way to produce their complex geometries. This is where the market finds itself, as the end-game of both OEM users and metal additive machine builders is full-scale production.
While technical challenges still remain, particularly as strategic users continue to test and develop new materials, metal additive manufacturing is making significant strides in transparency to prove the stability, predictability and repeatability of the process. Modules such as layer monitoring, laser power monitoring, melt pool monitoring and oxygen level monitoring are standard or under development industry-wide. As these new 3D technologies mature they’re accelerating the transition from prototyping to large-scale production, resulting in faster, cheaper and more flexible manufacturing processes.
Major OEMs have already proven that these optimized geometries meet the required quality and tensile strength for acceptance and approval to use in engines and as certification becomes standardized, we will only continue to see the use of metal additive manufacturing grow.