Abstract
Aerospace components and its coatings are required to possess excellent
surface properties namely: fatigue, wear and corrosion resistance over a
wide temperature range. Stainless steels, titanium, nickel superalloy
and more recently high entropy alloys have been used to improve the
exterior properties of these components. In this study, AlCoCrFeNiCu and
AlTiCrFeCoNi High Entropy Alloys were successfully fabricated using
laser additive manufacturing to produce coatings on a mild steel base
plate. The influence of the laser parameters (laser power and scan
speed) on the microstructure, hardness and coat geometry (height, width
and depth) were also investigated. The results revealed that coatings
homogeneously adhered to substrate. The optimum processing parameters
for both alloys with defect free structures at a preheat temperature of
400 °C, were at 1200-1600 W at 8-12 mm/s with the layers composed of
both FCC and BCC phases. The laser parameters affected the geometry,
quality and hardness. The results showed that optimizing the laser
parameters achieved by preheating temperature invariably improved the
performance of the alloys with potential coatings and aerospace
structural applications.