Nickel-based Inconel 718 is a very good candidate for selective laser melting (SLM). During the SLM process, Inconel 718 develops a complex and heterogeneous microstructure. A deep understandingofthemicrostructuralfeaturesoftheas-builtSLMmaterialisessentialforthedesignof aproperpost-processheattreatment. Inthisstudy,themicrostructureofas-builtSLMInconel718was investigated at diﬀerent length scales using optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Electron backscatter diﬀraction (EBSD) was also used to analyze the grain morphology and crystallographic texture. Grains elongated in the build direction and crossing several deposited layers were observed. The grains are not constrained by the laser tracks or by the melt pools, which indicates epitaxial growth controls the solidiﬁcation. Eachgrainiscomposedofﬁnecolumnardendritesthatdevelopalongoneoftheir<100>axesoriented inthedirectionofthelocalthermalgradient. Consequently,prominent<100>crystallographictexture was observed and the dendrites tend to grow to the build direction or with occasional change of 90◦ at the edge of the melt pools. At the dendrite length scale, the microsegregation of the alloying elements, interdendritic precipitates, and dislocations was also detected.
Texture and microstructural features at different length scales in Inconel 718 produced by selective laser melting / Calandri, M.; Yin, S.; Aldwell, B.; Calignano, F.; Lupoi, R.; Ugues, D.. - In: MATERIALS. - ISSN 1996-1944. - ELETTRONICO. - 12:8(2019).
|Titolo:||Texture and microstructural features at different length scales in Inconel 718 produced by selective laser melting|
|Data di pubblicazione:||2019|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.3390/ma12081293|
|Appare nelle tipologie:||1.1 Articolo in rivista|