Reduction of incandescent spatter with helium addition to the process gas during laser powder bed fusion of Ti-6Al-4V
Journal article, 2021

The effect of the process gas during laser powder bed fusion (L-PBF) was investigated using high-speed shadowgraphy while melting Ti-6Al-4V powder under high purity argon, helium, and a mixture of both, on a laboratory-scale machine. These recordings reveal that the generation of incandescent spatters can be reduced by at least 60% using pure helium and by ∼30% using addition of helium to argon in comparison to the use of traditional argon. The quantity of colder spatters appeared unaffected by the change of process gas. Different configurations of gas flow versus laser scanning direction were investigated and revealed that fumes and spatters are less accumulated at the laser spot with helium addition. Furthermore, the use of the argon–helium mixture proved to be as efficient as pure argon in the dragging and extraction of the fumes. Shadowgraphs revealed the more rapid expansion of fumes in helium-rich atmospheres, limiting the accumulation of scattering objects close to the laser spot and thus melt pool instability. These results were correlated to process snapshots on an industrial-scale system, confirming the reduction of hot spatter generation. Finally, the findings put in evidence the more rapid cooling of spatters with helium addition to the process gas – a promising aspect to limit powder bed degradation during L-PBF. In addition, the use of mixtures of helium and argon would be economically interesting compared to pure helium, typically more expensive than the traditionally used argon.

Shadowgraphy

Process gas

Helium

Spatters

Laser powder bed fusion

Ti-6Al-4V

Author

Camille Nicole Géraldine Pauzon

Chalmers, Industrial and Materials Science, Materials and manufacture

B. Hoppe

SLM Solutions Group AG

T. Pichler

Fraunhofer Institute for Laser Technology ILT

S. Dubiez-Le Goff

Linde GmbH

Pierre Forêt

Linde GmbH

T. Nguyen

Linde GmbH

Eduard Hryha

Chalmers, Industrial and Materials Science, Materials and manufacture

CIRP Journal of Manufacturing Science and Technology

1755-5817 (ISSN) 1878-0016 (eISSN)

Vol. 35 371-378

Driving Forces

Sustainable development

Subject Categories

Energy Engineering

Chemical Process Engineering

Metallurgy and Metallic Materials

Areas of Advance

Energy

DOI

10.1016/j.cirpj.2021.07.004

More information

Latest update

8/5/2021 6