Powder reuse affects laser metal deposition quality and mechanical properties
From powder to part: influence of virgin and recovered Inconel 625 powders on the DED-LP processability, microstructure and mechanical properties
Computational Engineering, Finance, and Science
Summary
Reusing metal powder in laser-based 3D printing can save resources, but it might change the quality of the printed parts. The authors studied a special metal called Inconel 625 and found that while reused powder looked similar, its oxygen content increased. This change could affect how the laser melts the material during printing, which in turn could impact the strength and flexibility of the parts. They also showed that pressing parts under high heat and pressure can make them less porous and more flexible but a bit less strong.
What this means in practice
- •For additive manufacturing engineers: Adjust powder handling and process settings when reusing metal powders to control final part quality in laser-based metal 3D printing.
- •For materials testing teams: Measure changes in oxygen content of reused powders to predict their impact on melt pool behavior and mechanical properties.
Authors
Romain Deloffre, Lorène Héraud, Julie Lartigau
Abstract
The reuse of metal powders in directed energy deposition using laser powder offers promising sustainability benefits for additive manufacturing, yet its impact on part quality remains unknown. This study investigates the influence of powder reuse on the directed energy deposition process of Inconel 625. Virgin powder was first characterized in terms of flowability, morphology, size and chemical composition, then used to manufacture parts under fixed process parameters. These parts were analysed through two configurations (as-built and hot isostatically pressed) to assess microstructural evolution and mechanical performance. Results show that hot isostatic pressing reduces porosity and promotes grain recrystallization, enhancing ductility while decreasing tensile strength. Recovered powders from one manufacturing cycle, were also characterized. Particle size distribution and morphology remained stable, interstitial contents, particularly oxygen, increased, potentially affecting laser-material interaction and melt pool behaviour in future production. These findings highlight the importance of evaluating powder reuse through a full-process approach, from powder to final part. Future work will focus on the tensile and fatigue performance of parts produced with recovered powders.