Surface and Structural modifications after laser irradiated of Al-Cu alloy in Oxygen environment for various fluences.

Changes in the surface and structural characteristics in Al-Cu alloy after laser irradiation in Oxygen gaseous environment has been examined. The specimens were irradiated using an Excimer (KrF) laser (248 nm, 18 nsec, 30 Hz) for varied fluences ranging from 3.8 J/cm2 to 5.5 J/cm . The irradiated targets' surface and structural alterations were examined using an X-ray diffractometer (XRD) and a scanning electron microscope (SEM). SEM investigation demonstrated the creation of various laser induced periodic surface structures (LIPSS). XRD investigation revealed that novel phases (Al2CuMg, AlCuO2) have been produced after laser irradiation in the presence of Oxygen gas. The unusual trend in the dislocation density and in crystallite size of Al-Cu alloy was noticed. Following laser irradiation of the Al-Cu alloy, there is a correlation between the surface and structural property changes.