Unveiling crack mitigation pathways in powder bed fusion–laser beam of CM247LC: an operando X-ray radiography study of Hf and nano-Y2O3 additions
Artikel i vetenskaplig tidskrift, 2026
Cracking presents a major hurdle for processing non-weldable Ni-base superalloys, such as CM247LC, by powder bed fusion–laser beam (PBF–LB). This study directly observes cracking behavior in standard CM247LC and two admixed alloys (CM247LC + 1 wt.% Hf and CM247LC + 1 wt.% nano-Y2O3) using operando synchrotron X-ray radiography synchronized with acoustic emission (AE). Our real-time data confirm extensive cracking in the standard alloy is identified to be primarily solidification cracking. Both Y2O3 and Hf additions mitigate solidification cracking, though through distinct mechanisms. Nano-Y2O3 addition alters the processing regime from keyhole to conduction mode. Scheil solidification simulations predict a narrower solidification range and lower solidification cracking index (SCI). This indicates that a combination of processing regime shift along with modification in solidification as the primary drivers for crack suppression upon addition of nano-Y2O3, despite increased lack of fusion and complex oxide formation. Hf-addition mitigated cracking via enhanced segregation at interdendritic regions, promoting beneficial carbides and improved liquid backfilling. Scheil simulations for alloy with Hf-addition predicted low SCI compared to standard CM247LC due to increased liquid availability in final solidification stages. These insights highlight that nearly crack-free PBF–LB of non-weldable superalloys can be achieved through both the powder modifications.
Solidification cracking
Operando radiography
X-ray computed tomography
Ni-base superalloy
Powder modification
PBF–LB
CM247LC
Författare
Ahmed Fardan Jabir Hussain
Chalmers, Industri- och materialvetenskap, Material och tillverkning
Gowtham Soundarapandiyan
Chalmers, Industri- och materialvetenskap, Material och tillverkning
Paul Scherrer Institute
Vigneashwara Pandiyan
Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa)
Turun Yliopisto
S. Van Petegem
Paul Scherrer Institut
E. Polatidis
Panepistimion Patron
Sofia Kazi
Chalmers, Industri- och materialvetenskap, Material och tillverkning
Sneha Goel
Teknologian Tutkimuskeskus (VTT)
Paul Scherrer Institut
Camille Pauzon
Université Grenoble Alpes
Chalmers, Industri- och materialvetenskap, Material och tillverkning
Federica Marone
Paul Scherrer Institut
Bharat Mehta
Thermo-Calc Software AB
Annapaola Parrilli
Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa)
Håkan Brodin
Siemens Energy
Chalmers, Industri- och materialvetenskap, Material och tillverkning
Eduard Hryha
Chalmers, Industri- och materialvetenskap, Material och tillverkning
Progress in Additive Manufacturing
23639512 (ISSN) 23639520 (eISSN)
Vol. In PressÄmneskategorier (SSIF 2025)
Metallurgi och metalliska material
Bearbetnings-, yt- och fogningsteknik
Styrkeområden
Materialvetenskap
DOI
10.1007/s40964-026-01876-5
Relaterade dataset
Dataset and code [dataset]
URI: https://gitlab.utu.fi/vpsora/Additive-Manufacturing-CM247-Subsurface-Process-Monitoring.