Antibacterial and Corrosion Studies on Nanosecond Pulse Laser Textured 304 L Stainless Steel Surfaces

The present paper describes results of study on surface texturing of 304 L stainless steel with 1064 nm Nd:YAG laser having average power of 15 W, pulse width of 100 ns, scan rate of 20 mm/s and repetition rate of 2 kHz. Detailed surface characterization was done using microscopic techniques, XRD and water contact angle measurement. Nanosecond laser texturing generated a thin remelted layer with wavy pattern on the surface that enhanced micro roughness and hydrophobicity. XRD pattern revealed peak broadening indicating reduction in cold working effect and increase in grain size. Laser assisted texturing were successfully introduced on 304 L SS with 1064 nm wavelength and 100 ns laser pulses of energy 7.5 mJ. Electrochemical polarization studies in chloride environments and exposure to bacterial culture confirmed that this surface modification has contributed to enhanced corrosion resistance and antibacterial activity. Thus, by tailoring the wettability, surface roughness and texture; nanosecond pulsed laser texturing approach succeeded in imparting desirable properties for cooling water system materials.