  The CrMnFeCoNi high-entropy alloy is highly printable and holds great
potential for structural applications. However, no significant discussions on
cyclic plasticity and fatigue damage in previous studies. This study provides
significant insights into the link between print processes, solidification
microstructure, cyclic plasticity and fatigue damage evolution in the alloy
fabricated by laser powder bed fusion. Thermodynamics-based predictions
(validated by scanning transmission electron microscopy (STEM) energy
dispersive X-ray spectroscopy (EDX)) showed that Cr, Co and Fe partition to the
core of the solidification cells, whilst Mn and Ni to the cell boundaries in
all considered print parameters. Both dislocation slip and deformation twinning
were found to be responsible for plastic deformation under monotonic loading.
However, the former was found to be the single dominant mechanism for cyclic
plasticity. The surface finish helped to substantially delay the crack
initiation and cause lack-of-fusion porosity to be the main source of crack
initiation. Most significantly, the scan strategies significantly affect grain
arrangements and grain dimensions, leading to noticeable effects on fatigue
crack propagation; in particular, the highest resistance crack propagation was
seen in the meander scan strategy with 0{\deg} rotation thanks to the most
columnar grains and the smallest spacing of grain boundaries along the crack
propagation path.
