Sòphia High Tech automates depowdering for aerospace parts

The aerospace industry has been a key adopter of metal additive manufacturing technology and an important driver of its evolution in recent years. At the same time, the industry has also been faced with certain challenges associated with additive manufacturing, including bottlenecks like manual post-processing. Fortunately, with advances in automated post-processing solutions, such as highly automated systems from German depowdering specialist Solukon, aerospace manufacturers are overcoming these hurdles and streamlining their AM operations.

Such has been the case at Sòphia High Tech, an aerospace company based out of Vesuviana, Italy that specializes in the design and production of 3D printed and CNC machined metal components. Sòphia High Tech makes a range of high-performance aerospace assemblies and parts, including propulsion components, satellite thrusters, fuel tanks, and primary and secondary structures for missiles and launchers, all while leveraging the advantages of metal AM, like design consolidation, complex geometries and lightweighting. 

When it comes to manufacturing these aerospace components, which often integrate internal cooling channels and other complex geometries, the effectiveness of post-processing steps like depowdering is vital to the success of the final part. Manual depowdering processes, such as vacuuming, hammering and blowing compressed air, are both time-consuming and are not guaranteed to remove all powder, which can lead to failed prints and safety issues. Automated and thorough depowdering solutions have thus been a priority for aerospace companies like Sòphia High Tech.

Depowdering a thrust combustion chamber 

To illustrate the impact of integrating automated depowdering, one doesn’t have to look further than Sòphia High Tech’s use of Solukon’s SFM-AT350 to depowder a thrust combustion chamber. The part, a monolithic regeneratively cooled thrust chamber assembly for use in a liquid rocket engine, was 3D printed on a TRUMPF TruPrint 3000 LPBF system from Inconel 718. 

Typically, thrust chamber assemblies are made from an array of different components, including the injector, main combustion chamber and nozzle, which are assembled using bolts of welding. By turning to metal AM, Sòphia engineers successfully streamlined the production process for the liquid rocket engine system by consolidating all these components into a single design. Not only has this approach simplified the production and assembly process, it has also resulted in a more lightweight thrust combustion chamber.

From a post-processing perspective, consolidating parts and integrating internal channels for optimal cooling presents certain challenges. In this case, the thrust combustion chamber included 500 mm of internal channels with rectangular sections measuring 1 mm in height, which would be difficult to remove loose powder from using manual techniques.

Sòphia High Tech therefore opted to use Solukon’s automated depowdering solution for medium-sized parts, the SFM-AT350. This system, capable of processing parts as heavy as 100 kg, removes powder systematically using a highly automated and safe process. Solukon describes how the depowdering process begins: “After the 3D printing by SLM process, the Solukon system removes the powder efficiently, while the part is securely held in place on the build plate. The system operates within an inert environment to ensure safety: the optimized chamber rapidly fills with protective gas, enabling the depowdering process to begin.”

Once the inert environment has been established, the SFM-AT350 uses pneumatic excitation and controlled movements (with 250 degrees of rotation along the horizontal axis and a rotatable turntable) to dislodge and remove loose powder. Sòphia’s Solukon hardware also integrates a high-frequency knocker (an optional accessory), which loosens any clumps of powder that may have formed in narrow channels. 

Notably, the sequence of motion is determined by SPR-Pathfinder, an intelligent software tool developed by Solukon that generates an optimal motion pattern based on the part’s CAD design. SPR-Pathfinder can even be used early on in the part design process: users can upload the CAD model and simulate the cleaning operation to ensure that powder can be fully removed from the geometry. The calculated rotations and excitation are thus highly effective at removing powder from even the most complex geometries, as was the case with the aerospace thrust combustion chamber.

In total, the SFM-AT350 was able to remove all loose powder from the consolidated aerospace component in a 40-minute cycle—a second cleaning cycle was carried out for validation purposes—and with little operator intervention. On top of that, the automated, self-contained process enhances the safety of the factory floor, by minimizing operator exposure to harmful metal powders. In fact, the metal powder cleaned from the part can also be recovered for recycling.

“The automated system has drastically improved our workflow,” said Dr. Giovanni Caferra, a lead operator at Sòphia High Tech. “It’s efficient, safe and the results are always consistent, which is something we couldn‘t achieve manually. With SPR-Pathfinder we don’t even need to do any programming for the machine anymore. It’s a very smooth depowdering workflow with a reliable cleaning quality.”

Ultimately, Solukon’s automated depowdering solution ensured that the thrust chamber assembly was clear from any powder residue before it advanced to CNC machining, while also minimizing depowdering time and labor requirements. 

In addition to the SFM-AT350, Solukon has a growing portfolio of hardware solutions to address the diverse needs of AM users, including the large SFM-AT1500-S, capable of processing metal parts weighing up to 2100 kg; and the SFM-AT350-E, which uses ultrasonic excitation to loosen and remove powder in a highly efficient way from metal 3D printed geometries, particularly useful for those with delicate features and internal channels. If you want to get in touch with the Solukon team click here or visit the official website.

This article was published in collaboration with Solukon.