Effect of the parameter „hatch length“ (a) on the microstructure (b) of Inconel 718

Effect of the parameter „hatch length“ (a) on the microstructure (b) of Inconel 718

Source: BAM, Department Materials Engineering, Division Micro Non-Destructive Testing, Division Weld Mechanics

Additive manufacturing of metallic materials is expected to revolutionize the advanced manufacturing industry in the coming years. Especially selective laser melting has been considered as the most promising technique for producing complex geometries from pre-alloyed metallic powders. The structural integrity of additive manufactured components is related to the proper control of process parameters used for the fabrication. Variation of the process parameters on the material properties is a largely unexplored area in the additive manufacturing research. Influence of the parameter hatch length on the material characteristics in selective laser melted samples of the nickel base super alloy Inconel 718 was analyzed and discussed in the present study.

It has been observed that the parameter hatch length has a significant impact on the microstructure development and crystallographic orientation in selective laser melted Inconel 718 samples. The hatch length variation influenced the heat transfer rates during selective laser melting, which in turn affected the microstructure development. Additionally, it was found that the residual stresses in the material are affected by the hatch length. This is due to different local melting and solidification mechanisms, which can be linked to the observed microstructure.

In summary, selective laser melting with a strict control of the process parameters can be utilized for adjusting the material characteristics and as an effective methodology to fabricate components with tailored mechanical properties.

Effect of hatch length on the development of microstructure, texture and residual stresses in selective laser melted superalloy Inconel 718
Naresh Nadammal, Sandra Cabeza, Tatiana Mishurova, Tobias Thiede, Arne Kromm, Christoph Seyfert, Lena Farahbod, Christoph Haberland, Judith Ann Schneider, Pedro Portella, Giovanni Bruno
Materials & Design, Volume 134, 15 November 2017, Pages 139-150
BAM Department Materials Engineering, Department Non-destructive testing, Division Micro Non-Destructive Testing, Department Component Safety, Division Weld Mechanics