Abstract Scope |
Metallic additive manufacturing (i.e., 3D printing) techniques typically generate melt pools with both higher thermal gradients and smaller length scales than those achieved through traditional manufacturing methods. Fluid flow during the build process is complex, and can vary locally based on machine parameters, powder properties, scanning strategy and many other mechanisms. Within melt pools, local composition can vary due to thermal gradients, fluid flow, solute segregation, selective vaporization, contaminants or other means. Analysis of the post-deposition compositional fluctuations in Ti-6Al-4V parts printed through electron beam melting, selective laser melting, and laser hot wire melting, have been used to showcase variations in local properties that lead to or influence the formation (and location) of defects, microstructure, and micro-texture across additive manufacturing processes. Revelations in compositional fluctuations shown through energy dispersive spectroscopy have been paired with microstructural imaging, electron backscatter diffraction, and nanoindentation to couple chemical, microstructural, and mechanical property variations. |