  The concept of alloying multiple principal elements at high concentrations
has led to the development of High Entropy Alloys (HEAs) with exceptional
mechanical properties, making them the focus of major recent scientific
endeavors. Geometrically complex HEAs with tailored microstructural
characteristics can be produced using additive manufacturing technologies such
as powder bed fusion (PBF). However, an in-depth study on the effect of process
thermal conditions during PBF is required to effectively fabricate HEAs with
desirable mechanical characteristics. Thus, in our present molecular dynamic
(MD) study we have explored the implication of PBF process thermal conditions
on the mechanical characteristics of FeNiCrCoCu HEA by systematically varying
laser scan speed from 0.4 {\AA}/ps to 0.1 {\AA}/ps, unidirectional and
reversing laser passes from 1 to 4, and laser power from 100 microwatts to 220
microwatts. Our investigation suggests that reducing the laser scanning speed
up to a critical velocity of 0.2 {\AA}/ps considerably improves mechanical
strengths, with further reduction creating severe surface defects. Decreased
ultimate tensile strength (UTS) is associated with the annihilation of the bulk
sessile dislocations during tensile straining marking an early yield failure.
Alternately, the material's strength could be improved by annealing with
several unidirectional laser passes over the same target region, resulting in
enhanced UTS due to subtler yield points. Increasing laser power aids in
ameliorating material density ultimately leading to higher UTS even in
non-dislocation-free structures. These findings will assist researchers to
understand the underlying effects and optimize process thermal parameters to
fabricate superior HEAs utilizing additive manufacturing.
