Development of adapted Ni-738 powder for additive manufacturing

In this study, Oerlikon AM and Fraunhofer ILT aimed to modify the material composition of Ni-738LC in order to reduce the crack susceptibility of the alloy powder during the LPBF (Powder bed fusion - Laser) process, while maintaining the mechanical properties of the alloy. In order to achieve this, the standard composition of Ni-738LC alloy powder was manufactured by LPBF, focusing on process parameters for a low and high crack counts as base line for further analysis. Experimental powders with modified Ni-738LC compositions were processed and compared in terms of cracking, hardness and microstructure. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analysis were used to understand the effect of modifications cracking behavior with reference to the standard composition. Finally, the mechanical properties of these alloy were compared via tensile tests at room temperature.