  Plastic inhomogeneity, particularly localised strain, is one of the main
mechanisms responsible for failures in engineering alloys. This work studied
the spatial arrangement and distribution of microstructure and their influence
in the plastic inhomogeneity of Inconel 718 fabricated by additive
manufacturing (AM). In particular, the density and spatial distribution of
geometrically necessary dislocations (GNDs) and the crystallographic texture
components were examined in relation to the spatial plastic deformation.
In-situ tensile testing coupled with microscopy and EBSD was performed to
understand the evolution of the as-built microstructure and its effect on the
spatial and temporal deformation behaviour. Bidirectional scan strategy with no
interlayer rotation resulted in highly ordered alternating arrangements of
coarse Goss-like {110}<001> textured grains separated by fine Cube-like
{100}<001> textured grains. This strategy also resulted in an overall high
density of dislocations (in particular GNDs) with a regular pattern: the fine
grains contained very high GND density while the coarse grains contained less
GNDs but they were oriented to be perpendicular to the scan direction. Although
this strategy resulted in a dominant Cube texture that is desirable for
isotropy, the Cube texture gradually weakened and the undesirable Goss
component increased during plastic deformation. Together with the columnar
grain morphology and aligned GND arrangement, such texture evolution caused
intense plastic inhomogeneity during deformation. Replacing the bidirectional
strategy with a chessboard strategy involving a 67{\deg} layer rotation
resulted in a lower GND density and much more random distribution of
crystallographic texture and GNDs, with a dominant Cube component (and lower
Goss texture) that remained stable throughout plastic deformation, reducing the
plastic inhomogeneity.
