Effect of laser powder bed fusion process parameters on the microstructural characteristics of Ni-Cr based alloy 625

Nowadays, additive manufacturing is having increasing use thanks to its ability to overcome the constraints associated with conventional manufacturing methods. Additive manufacturing has made it possible to save costs and time, also allowing the production of items with complex geometries. The study aims to identify how the microstructural characteristics of Ni-Cr based alloy 625, produced through laser powder bed fusion technology, vary by changing the process parameters. The same experiments are done on the same samples before and after heat treatment to see how the formation of secondary phases improves the mechanical properties of the superalloy. Results highlighted different values of porosity, subgrain size and hardness for samples produced with different scan strategy and layer thickness, revealing how the variation of the parameters affects the properties of the alloy.