Coating and prototyping of single-phase iron aluminide by laser cladding

Laser cladding with powder blends of iron and aluminium was performed using a 500-W diode laser and a coaxial powder nozzle. Mild steel, pure nickel and aluminium alloy were used as substrate materials. The results were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. Completely crack-free, single-phase Fe3Al coatings could be achieved on steel. The coating on nickel consisted of FeAl. Despite the high cooling rates, which normally occur during laser cladding, the grains within the coatings were rather coarse. Laser cladding on aluminium, on the other hand, led to cracking. Furthermore, it could be shown in this work that it is possible to prototype 3-D iron aluminide structures by in situ laser cladding.