Study of Micro/Nano Structuring and Mechanical Properties of KrF Excimer Laser Irradiated Al for Aerospace Industry and Surface Engineering Applications

Abstract

Micro/nano structuring of KrF Excimer laser-irradiated Aluminum (Al) has been correlated with laser-produced structural and mechanical changes. The effect of non-reactive Argon (Ar) and reactive Oxygen (O2) environments on the surface, structural and mechanical characteristics of nano-second pulsed laser-ablated Aluminum (Al) has been revealed. KrF Excimer laser with pulse duration 20 ns, central wavelength of 248 nm and repetition rate of was utilized for this purpose. Exposure of targets has been carried out for 0.86, 1, 1.13 and 1.27 J.cm−2 laser fluences in non-reactive (Ar) and reactive (O2) ambient environments at a pressure of 100 torr. A variety of characteristics of the irradiated targets like the morphology of the surface, chemical composition, crystallinity and nano hardness were investigated by using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffractometer (XRD), Raman spectroscopy and Nanohardness tester techniques, respectively. The nature (reactive or non-reactive) and pressure of gas played an important role in modification of materials. In this study, a strong correlation is observed between the surface structuring, chemical composition, residual stress variation and the variation in hardness of Al surface after ablation in both ambient (Ar, O2). In the case of reactive environment (O2), the interplay among the deposition of laser energy and species of plasma of ambient gas enhances chemical reactivity, which causes the formation of oxides of aluminum (AlO, Al2O3) with high mechanical strength. That makes it useful in the field of process and aerospace industry as well as in surface engineering.

Nanosecond Laser Induced Surface Structuring of Cadmium after Ablation in Air and Propanol Ambient

“…SEM analysis is utilized for the investigation of variation in surface morphology, average ablation depth (δ) and ablated diameter (D) of ablated region for varying number of pulses, i.e., 500, 1000, 1500, and 2000. ImageJ software is used for the evaluation of δ and D, whereas the ablated volume ( V ) is calculated by using the following formula [ 24 ]: …”

“…This variation in values of δ, D and V is related to the variation in energy absorption with the variation in number of pulses. The increase in ablated volume and depth might be related to the fact that less or no thermal conduction and less plasma expansion is taking place, causing the target surface to absorb maximum part of energy, which in turn causes an increase in values of δ, D and V [ 24 ]. With the increase in number of pulses to 1500, the conduction of heat on the irradiated Cd surface takes place, causing the reduction in energy absorption for target ablation.…”

On-Demand Wettability via Combining fs Laser Surface Structuring and Thermal Post-Treatment

“…General surface properties, including wetting, are very important in a multitude of fields, including aerospace [ 45 ], maritime [ 46 ], heavy industry [ 47 ], and medicine [ 48 ]. At the same time, while various pilot-level tests are presented in the literature, there are still a multitude of challenges separating academic achievements from widespread use.…”