The Alumina Film Nanomorphology Formed to Improve the Corrosion Resistance of Al-2.0 wt% Fe Alloy as Result of the Laser Surface Melting Technique Applied

Abstract

The laser surface remelting (LSR) treatment was performed to Al - 2.0 wt% Fe alloy with a 2 kW Yb-fiber laser (IPG YLR-2000S). The substrate and laser-treated material characterization w ere executed using different techniques . Among them, the microstructure was analyzed by optical microscope, SEM, low-angle X-ray diffraction (LAXRD) and the corrosion test was made in aerated solution of 0.1 M H 2 SO 4 at a temperature of 25 ° C ± 0.5 ° C. As result was shown , the micrograph of LSR-treated material displaying can be a fine cellular structure and the existence of certain nano - porosities and a similar to a nano-dendritic growth was observed too. The characteristic of melted zone was constituted of metastable phases according to the result of x-rays and the behavior corrosion as a result of the LSR-treated sample, which it was shown to be more resistant to corrosion than the untreated sample. A comparative study was carried out of the cyclic polarization of the laser-treated and untreated samples, demonstrating that the reduction and oxidation reverse peaks were not observed and being the cyclic polarization behavior wa s of irreversible character in both samples, however, the LSR-treated sample propitious the passivity on the surface also reduc ed the corrosion phenomena. Wherefore, this type of laser-treated alloy can be applied in the aerospace, aeronautic and automobilist industries.