Advanced Manufacturing

The provided research paper introduces a novel test artifact specifically designed for laser powder bed fusion (LPBF), a metal additive manufacturing technique. Recognizing the lack of a widely adopted standard artifact beyond basic geometric assessments, the authors developed a compact design with features to evaluate a comprehensive range of factors crucial for LPBF qualification. This single artifact allows for the assessment of microstructure, residual stress, chemical composition, surface integrity, geometric accuracy, internal features, and mechanical properties. The paper details the design considerations and features of the artifact and presents preliminary results from its fabrication on two different LPBF systems, demonstrating its potential for standardizing testing and accelerating the adoption of LPBF for critical applications through a proposed global data exchange program.

Laser powder bed fusion (LPBF) relies on inert gases to prevent oxidation of reactive metals, which can weaken 3D-printed parts. Existing integrated oxygen sensors in LPBF machines lack sufficient accuracy and stability for producing high-quality components. To address this, a new standalone module with three galvanic fuel cell oxygen sensors has been developed. Each sensor operates within a specific oxygen concentration range (10,000 ppm, 1,000 ppm, and 10 ppm), activated sequentially to provide precise readings. This system uses solenoid valves and pumps to control gas flow and ensure accurate oxygen level monitoring via a standard KF-40 fitting.

This research article uses Magnetic Resonance Velocimetry (MRV), a novel approach, to map the three-dimensional argon gas flow within a commercial metal additive manufacturing (PBF-LB/M) machine's build chamber for the first time. A scaled model of the EOS M290 system was employed to conduct MRV measurements, revealing complex flow patterns including jets, recirculation zones, and separation regions. The study correlates these flow characteristics with melt pool depths resulting from laser scans on titanium plates, demonstrating a direct link between gas flow quality and part quality. The findings highlight the impact of inadequate gas flow on laser power delivery and suggest potential improvements to build chamber design to achieve more uniform flow. An additional vent was implemented to demonstrate that improving problematic flow regions increases melt pool depth.

This research paper introduces a novel, user-friendly installation qualification (IQ) method for the scanner subsystem of laser-based powder bed fusion (PBF-LB/M) metal additive manufacturing machines. The method uses a simple plate melt test to assess various scanner performance aspects, including laser and scanner delays, acceleration, dimensional accuracy, and slicer software interpretation, overcoming the limitations of current, costly, and time-consuming standards. Testing on four different PBF-LB/M machines revealed significant machine-to-machine variations in scanner performance, highlighting the need for improved standardization and user-accessible calibration tools. The proposed method aims to empower users to qualify their systems and identify potential issues requiring OEM intervention. Further research will focus on quantifying the test results and conducting a cost-benefit analysis.