Laser ablation of phosphor bronze for superhydrophobic surface

Copper alloys have antibacterial characteristics and improved hydrophobicity of alloy surface minimises the strains left over by the infected fluids, which is vital for hygienic concerns in medical applications. In the present study, laser ablation of phosphor bronze surface is carried out to improve surface hydrophobicity. Morphology and metallurgy of the laser ablated surfaces are characterised using scanning electron microscope, energy dispersive X-ray spectroscopy, and X-ray diffraction. The surface texture is analysed incorporating atomic force microscopy. Surface hydrophobicity is assessed through the contact angle measurements. Residual stress formed in the ablated region is determined using the X-ray diffraction technique and the friction coefficient of the ablated surface is evaluated via scratch tests. The findings reveal that laser ablation of phosphor bronze provides superhydrophobic surface, high hardness, reasonably low residual stresses and low friction coefficient. The average contact angle of 140 degrees is resulted at the laser ablated surface, which is significantly higher than that of as received surface.