Figure 13 D.O.E Surface Plot Showing the Effect of Laser
Parameters on the Microhardness of AlTiCrFeCoNi HEA (a) Stage 1 of
Experiments (b) Stage 2 of Experiments
Consequently, the AlTiCrFeCoNi alloy’s had higher hardness values after
the first stage of experiments but showed a decline at the second stage
of experiments with an average hardness ranging from 811-387 HV compared
to AlCoCrFeNiCu HEA which ranged from 389-837 HV after stage one and two
of the experiments. Generally, both alloys showed good hardness values
attributed to the transition in the lattice structure from FCC to BCC,
which contributes to the increment in hardness values. More so, the
rapid solidification during laser additive manufacturing leads to
excellent microhardness properties compared with alloys fabricated by
conventional methods; arc melting [97]. The hardness properties of
AlTiCrFeCoNi HEA make it favourable for wear resistant coating
applications. Due to the AlCoCrFeNiCu alloy’s composition, the highest
hardness values occurred at an increased laser power and scan speed
while the AlTiCrFeCoNi occurred at a lower power and high scan speed as
shown in Figure 14 (a) and (b).