Effect of surface modification by nanosecond laser texturing on pure Zn biodegradability

The development of bioresorbable metallic alloys, which are being actively researched as materials for temporary medical implants, poses considerable challenges under the processing, metallurgical and corrosion points of view. Their degradation behaviour in physiological environment is strongly connected to their surface topography and chemistry, which shall be carefully addressed in the view of spreading the fielding of such alloys in the biomedical sector. The present work addresses the possibility of controlling the degradation behaviour of pure Zn though laser surface modification by nanosecond laser texturing. The effect of irradiated energy on the surface topography and the microstructure was studied and the resulting degradation behaviour was investigated. It was found that laser texturing can deeply affect surface roughness and the presence of oxides, due to the rapid remelting induced by the laser pulses in the nanosecond order. Therefore, different degradation behaviours were found to be associated to the surfaces, laser treated at low and high energy, resulting in a diversification of the nature and morphology of the degradation products.