Use Case: Automated Depowdering of a Thrust Combustion Chamber

Automated depowdering is essential for aerospace components with intricate internal structures, ensuring safety, certification, and efficiency. Sophia High Tech’s one-piece Thrust Combustion Chamber, produced using Selective Laser Melting with Inconel 718, benefits from Solukon SPR® technology to remove residual powder before CNC machining, streamlining production and improving quality.

Introduction

The demand for automated depowdering solutions is particularly high for complex geometries, with a prime example being the aerospace sector. In this industry, parts often feature intricate internal structures, making thorough depowdering crucial. Companies in aerospace require full transparency, certification, and improved occupational health and safety, making automated depowdering a vital part of the production process.

A noteworthy case study is the depowdering of a Thrust Combustion Chamber manufactured by Sòphia High Tech using the SLM [Selective Laser Melting] process with Inconel 718. Sophia developed and built a lightweight one-piece regeneratively-cooled thrust chamber assembly (TCA) for liquid rocket engines. Liquid rocket engines create thrust through the expansion of combusted propellants within the TCA. The standard process for manufacturing thrust chamber assemblies (TCAs) involves separately constructing the injector, main combustion chamber, and nozzle, which are then connected using bolts or welds at the joints. Sophia‘s engineers are streamlining this process by eliminating complex joints and producing a single-piece TCA using advanced additive manufacturing technologies.

The depowdering process is essential to ensure that no powder residues are inside the TCA before being processed to the CNC Machining phase. The unique and advanced Solukon SPR® depowdering technology enhances operational efficiency and safety during the manufacturing process.

Facts and Figures about the application and depowdering process

Build plate dimensions (B x T x H)	Ø 300 x 270 mm
Printer	TRUMPF TruPrint 3000
Material	Inconel 718
Application	Thrust Combustion Chamber (Aerospace)
Structure / surface	Complex internal channels with rectangular sections (1 mm height, 3-5 mm length, total channel length of 500 mm
Duration of automated depowdering	40 minutes per cycle (2 SPR-Pathfinder cycles with 216 steps)
Depowdering system	SFM-AT350 with a high-frequency knocker
Mode used	Intel Mode

The depowdering process for aerospace parts at Sophia High Tech

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. Using the intelligent mode powered by SPR-Pathfinder software, the depowdering process is highly efficient. SPR-Pathfinder requires only the part‘s CAD file to calculate the optimal motion sequence for the Solukon system, eliminating the need for manual programming. During the automated cleaning process, systematic vibrations facilitate the flow of powder from complex geometries, including the intricate channels of the combustion chamber. The SFM-AT350’s integrated high-frequency knocker efficiently removes any residual powder or powder cloggs, achieving thorough depowdering in approximately 40 minutes.

Safety and efficiency

The automated depowdering process significantly enhances safety for operators, as all operations can be performed
within a sealed process chamber under inert condition,minimizing exposure to metallic powders. A thorough cleaning of the system is necessary to prevent cross-contamination, particularly when recycling recovered powders.

Why is Solukon the right partner for depowdering?

Solukon technology plays a crucial role in improving occupational health and safety at Sophia High Tech. By automating
the depowdering process, the risk of operator exposure to residual powders is significantly reduced. Operators
appreciate the efficiency and reliability of the SFM-AT350, which simplifies the cleaning process and provides a more
consistent outcome compared to manual methods.

„The automated system has drastically improved our workflow. 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,“ says Dr. Giovanni Caferra, one of the lead operators at Sophia High Tech.

Overall, the SFM-AT350 is low-maintenance and of ultra-high quality, making it a highly recommended choice for other
additive manufacturers in the aerospace sector.