Unveiling crack mitigation pathways in powder bed fusion–laser beam of CM247LC: an operando X-ray radiography study of Hf and nano-Y2O3 additions
Journal article, 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
Author
Ahmed Fardan Jabir Hussain
Chalmers, Industrial and Materials Science, Materials and manufacture
Gowtham Soundarapandiyan
Chalmers, Industrial and Materials Science, Materials and manufacture
Paul Scherrer Institute
Vigneashwara Pandiyan
Swiss Federal Laboratories for Materials Science and Technology (Empa)
University of Turku
S. Van Petegem
Paul Scherrer Institut
E. Polatidis
Universityof Patras
Sofia Kazi
Chalmers, Industrial and Materials Science, Materials and manufacture
Sneha Goel
Technical Research Centre of Finland (VTT)
Paul Scherrer Institut
Camille Pauzon
Grenoble Alpes University
Chalmers, Industrial and Materials Science, Materials and manufacture
Federica Marone
Paul Scherrer Institut
Bharat Mehta
Thermo-Calc Software AB
Annapaola Parrilli
Swiss Federal Laboratories for Materials Science and Technology (Empa)
Håkan Brodin
Siemens Energy
Chalmers, Industrial and Materials Science, Materials and manufacture
Eduard Hryha
Chalmers, Industrial and Materials Science, Materials and manufacture
Progress in Additive Manufacturing
23639512 (ISSN) 23639520 (eISSN)
Vol. In PressSubject Categories (SSIF 2025)
Metallurgy and Metallic Materials
Manufacturing, Surface and Joining Technology
Areas of Advance
Materials Science
DOI
10.1007/s40964-026-01876-5
Related datasets
Dataset and code [dataset]
URI: https://gitlab.utu.fi/vpsora/Additive-Manufacturing-CM247-Subsurface-Process-Monitoring.