Invited: Predicting Part Quality via Correlative Modeling of Laser Powder Bed Fusion Surface Characteristics to Microstructure

Laser powder bed fusion (L-PBF) additively manufactured parts are built in a layer-wise fashion, with each layer formed by a series of material tracks. The processing parameters govern the uniformity of these tracks and, in turn, influence the surface condition. These parameters also effect the overall part quality by impacting the as-built microstructure including the formation of defects such as porosity. As part of an on-going study, this work explores the relationship between surface features and microstructure (e.g. grain and pore morphology and distribution) of L-PBF parts in three different commonly used alloys, namely 17-4PH, CoCrMo, and IN718. Laser scanning confocal microscopy was used to generate 3-D height maps and obtain high resolution surface profiles. Both 2-D and 3-D methods were used to characterize the microstructure. This work aims to uncover a fundamental process-structure-property relationship that is easily analyzed by characterizing the top surface of an additively produced part. The goal of this endeavor is to build sufficient confidence in the correlation between surface features and part quality such that it can be used to predict final part performance or for process health monitoring.