Effect of helium as process gas on laser powder bed fusion of Ti-6Al-4V studied with operando diffraction and radiography
Journal article, 2022
The utilisation of helium as process gas in laser powder bed fusion limits the generation of Ti-6Al-4V hot and incandescent spatters and enhances their cooling rate. In the present study, operando X-ray diffraction using synchrotron X-rays permits to verify that the cooling rates experienced by the deposited material are not significantly affected by the process gas unlike spatters. Topography measurements of the top printed surface reveal lower roughness of He-produced samples, attributed to the previously observed reduction of spatters with He and thus a reduction of redepositions on the powder bed and printed surfaces. Operando radiography provides with insights on the spatter formation mechanisms namely particle entrainment, agglomeration, melting and spheroidization.Highlights The top surface average roughness of samples produced with He is lower than that of Ar equivalent Deposited Ti-6Al-4V cooling rates during LPBF are not significantly affected by the use of He Grain size and orientation of Ti-6Al-4V is similar when processing under Ar, He, and a mixture of both Operando radiography permits to identify the mechanisms of Ti-6Al-4V spatter formation.
spatters
process gas
operando radiography
Helium
laser powder bed fusion
operando X-ray diffraction
Author
Camille Nicole Géraldine Pauzon
Chalmers, Industrial and Materials Science, Materials and manufacture
S. Van Petegem
Paul Scherrer Institut
Eduard Hryha
Chalmers, Industrial and Materials Science, Materials and manufacture
Cynthia Sin Ting Chang
Paul Scherrer Institut
Analytics with Neutrons And X-rays for Advanced Manufacturing ANAXAM
Samy Hocine
Paul Scherrer Institut
Swiss Federal Institute of Technology in Lausanne (EPFL)
Helena Van Swygenhoven
Swiss Federal Institute of Technology in Lausanne (EPFL)
Paul Scherrer Institut
Charlotte de Formanoir
Swiss Federal Institute of Technology in Lausanne (EPFL)
S. Dubiez-Le Goff
Linde GmbH
European Journal of Materials
26889277 (eISSN)
Vol. 2 1 422-435Subject Categories (SSIF 2011)
Energy Engineering
Manufacturing, Surface and Joining Technology
Materials Chemistry
Metallurgy and Metallic Materials
DOI
10.1080/26889277.2022.2081622