Residual stresses and porosity in Ti-6Al-4V produced by laser powder bed fusion as a function of process atmosphere and component design
Artikel i vetenskaplig tidskrift, 2021

The influence of the process gas, laser scan speed, and sample thickness on the build-up of residual stresses and porosity in Ti-6Al-4V produced by laser powder bed fusion was studied. Pure argon and helium, as well as a mixture of those (30% helium), were employed to establish process atmospheres with a low residual oxygen content of 100 ppm O-2. The results highlight that the subsurface residual stresses measured by X-ray diffraction were significantly lower in the thin samples (220 MPa) than in the cuboid samples (645 MPa). This difference was attributed to the shorter laser vector length, resulting in heat accumulation and thus in-situ stress relief. The addition of helium to the process gas did not introduce additional subsurface residual stresses in the simple geometries, even for the increased scanning speed. Finally, larger deflection was found in the cantilever built under helium (after removal from the baseplate), than in those produced under argon and an argon-helium mixture. This result demonstrates that complex designs involving large scanned areas could be subjected to higher residual stress when manufactured under helium due to the gas's high thermal conductivity, heat capacity, and thermal diffusivity.

Laser powder bed fusion

Residual stresses



Process atmosphere


Camille Nicole Géraldine Pauzon

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Tatiana Mishurova

Bundesanstalt für Materialforschung und -prüfung (BAM)

Sergei Evsevleev

Bundesanstalt für Materialforschung und -prüfung (BAM)

Sophie Dubiez Le Goff

Linde GmbH

Saravana Murugesan

Linde GmbH

Giovanni Bruno

Universität Potsdam

Bundesanstalt für Materialforschung und -prüfung (BAM)

Eduard Hryha

Chalmers, Industri- och materialvetenskap, Material och tillverkning

Additive Manufacturing

2214-8604 (eISSN)

Vol. 47 102340

Användning av storskalig infrastruktur för att studera effekten av processgas i laserpulverbäddssmältning

VINNOVA (2019-05272), 2020-02-03 -- 2020-12-30.





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