Yb-fiber laser beam effects on the surface modification of Al–Fe aerospace alloy obtaining weld filet structures, low fine porosity and corrosion resistance

Yb-fiber laser beam was used successfully to irradiate Al–1.5 wt.% Fe alloy, modifying its surface to improve its corrosion resistance for aerospace applications. Laser-treated samples were examined by optical microscopy, scanning electron microscopy, energy dispersive X-ray diffraction (EDX), and low-angle X-ray diffraction (LA-XRD), and tested by Vickers microhardness. The alloy's corrosion resistance was tested by exposure to H 2SO 4 solution, Tafel plots, polarization, and corrosion potentials. The results reveal the formation of weld filet structures with metastable phases and finely dispersed precipitates. The creation of a finely porous layer of protective coating produced during the rapid remelting process contributed to increase the corrosion resistance of laser-treated samples when compared with untreated samples. The Yb-fiber laser beam technology applied to the surface treatment of aluminum alloys proved efficient in augmenting their corrosion resistance, thus deserving further investigation for aerospace and automotive applications. ► The Yb-fiber laser beam produces surface modifications to improve corrosion resistance Al–Fe alloy. ► Different metastable phases and a stable phase were obtained in the laser-treated Al–1.5 wt.% Fe alloy. ► The filet weld regions showed higher microhardness. ► The surface treated by laser remelting processes promoted a protector passivating film. ► Laser treatment method may find several applications, in the aerospace and automotive industries.