Healing cracks in selective laser melting by 3D laser shock peening

Selective Laser Melting (SLM) of Ni-based superalloys such as CM247LC is prone to weld-cracking. This paper investigates how to suppress cracks by repeatedly applying Laser Shock Peening (LSP) during the building phase of SLM. Samples made of CM247LC were processed with different LSP parameters, and the influence on bulk crack density has been quantified. It was observed that for all chosen conditions, a significant decrease of up to 95% could be achieved, demonstrating the potential of the new hybrid 3D LSP method in improving SLM processability of alloys sensitive to cracking.