Researchers have made significant strides in enhancing metal alloys for use in demanding environments like gas turbines. A recent study focused on optimizing the Powder Bed Fusion – Laser Beam (PBF-LB) method without inducing cracks in a metal alloy known for its resilience under extreme temperatures.
The researchers targeted the issue of crack formation during the additive manufacturing method PBF-LB. The study centred around the high γ’ Ni-base superalloy CM247LC, a type of strong alloy that is difficult to shape when using PBF-LB, due to its susceptibility to cracking. However, these alloys hold significant interest for aerospace and gas turbine industries due to their high-temperature performance.
By adjusting laser parameters such as power, speed, and hatch spacing, while maintaining a consistent layer thickness, researchers aimed to understand the impact of process parameters on microstructure, residual stresses, and solidification cracking.
Key findings highlight the importance of controlling melt pool dimensions, with shallower melt pools and significant overlap showing promise in reducing tiny cracks in the metal and making it stronger. This is achieved by printing the metal at low line energy density, that is given by the ratio of laser power and speed.
Preliminary tests also suggest that these insights may be applicable to other crack-prone alloys. Furthermore, significant progress has been made in minimizing cracks in the metal alloy, with opportunities for further process refinement.
About the research
The research has been published in the article Fine-Tuning Melt Pools and Microstructures: Taming Cracks in Powder Bed Fusion—Laser Beam of a non-weldable Ni-base Superalloy, published in Materialia.
The MAGDA project
The research is part of the research project MAGDA, Materials for green hydrogen fueled gas turbines through additive manufacturing.
- Doctoral Student, Materials and Manufacture, Industrial and Materials Science
- Full Professor, Materials and Manufacture, Industrial and Materials Science