Crystallographic Variability in Additive Manufacturing

Abstract

The crystallographic textures produced during additive manufacturing can be understood, predicted, and manipulated by varying the grain nucleation and growth processes. The resultant textures are primarily dictated by the melt pool geometry, which defines the local thermal gradient and thus the preferred crystal growth directions, as well as the scan strategy, which controls the propagation of grain orientations into subsequent layers. This texture can be diluted through heterogeneous nucleation of new grain orientations, which can occur through a variety of mechanisms. This ability to control the texture during additive manufacturing can enable the location-specific control of properties as a function of position in the build.