Tobias Petzinger, an applications specialist at AMCM, focuses on benchmarking and application-related projects for the company’s largest machines. His role involves supporting customers, mainly in the aerospace and defense sectors, to optimize their use of AMCM’s technology. “Most of the time, their applications are pretty critical,” Petzinger noted, emphasizing the complexity and precision required for large-scale additive manufacturing.
Petzinger described the process of convincing customers about the efficacy of transitioning from smaller to larger machines. “The step from a small machine to a really big part, it’s not that easy,” he said, pointing out the significant increase in build times and the necessity of robust, interruption-free machines. For instance, building a combustion chamber can take up to two weeks, during which even a minor interruption can render the part unusable.
The challenges increase with part size, particularly in thermal management. “As soon as the parts are tall and bulky, you really run into overheating,” Petzinger explained. This issue is exacerbated when working with high-performance materials. If a cooling channel within a combustion chamber becomes clogged due to overheating, the part could fail catastrophically during a hot fire test.
Additive manufacturing has enabled the private space boom. “It seems like there is no going around additive manufacturing for successful applications,” he asserts. The ability to rapidly iterate designs without overhauling the entire manufacturing process is a significant advantage, particularly in the fast-paced space industry.
Yet startups in the sector face distinct challenges and opportunities. Petzinger acknowledged that these companies often strive to maximize in-house knowledge while also needing to deliver quickly due to limited venture capital, especially in Europe. “They really need to hit their milestones as soon as possible,” he noted. This pressure leads to high-risk endeavors, such as printing parts for immediate hot fire testing. Despite these risks, Petzinger remarked, “It’s hard for us to guarantee that it’s going to be fine because there are so many variables.”
Additive manufacturing for large, complex structures in the space industry
Thermal management is one particular challenge to solve during the build process and addressing residual stress. Petzinger highlights the complexity of maintaining optimal conditions: “You really have to think about how you want to orientate the part… where you tend to have pretty high overheating.”
The choice of materials is crucial. For instance, copper and chromium zirconium tend to overheat quickly, while titanium benefits from higher temperatures by reducing thermal stresses. Inconel 718, a common material in aerospace and defense, poses challenges due to the mechanical and thermal stresses introduced during the build.
Simulation software plays an increasingly vital role. Petzinger notes significant advancements in process simulation, which now allows for more accurate predictions and reduced iteration times. “Simulation is getting more and more important, especially as the part size increases,” he says, emphasizing the need for accurate simulations before initiating costly large-scale builds.
AMCM’s approach involves using smaller machines to develop parameters and critical geometries before scaling up. “We use the same scan optics, the same process parameters on every machine,” Petzinger explains, ensuring a high degree of transferability from smaller to larger systems.
Discussing the specifics of larger machines, particularly the M 4K and beyond, Petzinger notes several key differences from smaller systems. The M 4K requires around 1.5 tonnes of powder for a build, necessitating robust powder supply and sieving systems. “Just imagine if you have to sieve one and a half tonnes of powder before starting a job,” he remarks, illustrating the logistical challenges.
The machine’s construction must be extremely robust to handle the substantial weight and ensure precise movement of components. Thermal management is another critical aspect, with active cooling systems for the process chamber, building chamber, scanners, and lasers to maintain consistent temperatures. Additionally, the filtration system is designed for continuous operation, allowing waste bin exchanges without halting the process, crucial for long-build jobs.
Advances in additive manufacturing for aerospace and space applications
While advanced alloys are behind a number of advanced applications, other developments in AM also play an important role.
Beam shaping technology represents a cutting-edge development in the field. Petzinger describes how AMCM’s collaboration with Enlite enables the use of lasers that can change their beam shape during the build process. This innovation significantly enhances productivity and precision. “You can be two and a half times, or more, faster per layer,” Petzinger notes, illustrating the substantial efficiency gains. The ability to switch between a fine beam for detailed work and a broader beam for faster infill adds versatility, making the technology attractive to both academic and industrial players.
AMCM’s collaboration with NLIGHT on beam shaping technology represents a significant advancement.
But what is the technology capable of, what has been created so far, and what is next?
One notable project is the Hyperganic Aerospike Nozzle, which exemplifies the synergy of intelligent design algorithms and high-performance materials like copper chromium zirconium. This project showcases the strengths of AM by producing components unachievable through traditional manufacturing methods.
Looking ahead, Petzinger sees broader adoption of AM in Europe, driven by a growing recognition of its economic viability. He observes that even established suppliers are investing in large AM machines, reflecting a shift toward domestic manufacturing for greater reliability. “More companies in Europe are seeing the business case behind it,” he notes, attributing this trend to the recent disruptions in global supply chains.
Petzinger also anticipates advancements in multi-material printing, which would revolutionize manufacturing by integrating diverse material properties within a single build. This capability would streamline processes that currently require multiple manufacturing steps. “You can do even more complex structures with multi-material printing,” he says, envisioning applications that seamlessly combine materials for optimized performance.
The continuous evolution of AM technology promises significant impacts across regulated industries, particularly defense and aerospace. Petzinger highlights the dynamic interplay between startups and established companies in driving innovation. “You work together with knowledgeable customers who know what AM can do,” he says, emphasizing the collaborative nature of advancements in this field.
As AM technology matures, its role in transforming manufacturing processes and enabling new aerospace applications becomes increasingly clear, positioning it as a critical technology for future developments.
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