|About this Abstract
||Materials Science & Technology 2019
||Additive Manufacturing of Metals: Microstructure and Material Properties of Nickel-based Alloys
||Crystallographic Characterization of Nickel-based Alloys by Optical Microscopy
||Mallory Wittwer, Ekta Jain, Yeoh Yong-Chen, Bernard Gaskey, Matteo Seita
|On-Site Speaker (Planned)
Owing to their printability and high performance, nickel-based alloys are candidate materials for large-scale additive manufacturing (AM) of parts for aerospace applications. The properties of these materials depend directly on crystallographic orientation, which varies extensively across batches and is difficult to characterize using conventional techniques. In this study, we present a technique based on directional reflectance microscopy (DRM) to assess microstructural information in nickel alloy specimens manufactured by directed energy deposition. DRM involves capturing a series of optical micrographs at various illumination angles and collating them to determine the directional reflectance distribution (DRD) of individual grains. The DRD specifies how grains reflect light as a result of their surface structure, which in turn is function of the underlying crystal orientation. We demonstrate that machine learning algorithms can be used to model the relationship between DRDs and crystal orientation, thereby enabling rapid and high-throughput assessment of crystallographic texture in AM materials.
||Planned: At-meeting proceedings