Some Novel Studies on Growth and Characterization of Femtosecond Laser Induced Micro and Nanostructures on Titanium

Abstract

newline Titanium (Ti) and Zinc (Zn) metal having surface micro/nano structures are very much promising for various applications like Bioimplant, Tribology, Battery etc. Laser texturing method is one of the best methods to generate highly reproducible micro/nano structure on the surface of all types of solid-state materials like metals, semiconductors, dielectrics, ceramics, and polymers etc. By adjusting the laser parameters like wavelength, polarization, pulse duration, pulse number, pulse fluence; the shape, size and orientation of the created structures can be controlled very precisely. In this work, we therefore did some detail investigations on growth of micro/nanostructures on the aforementioned metals. Particularly in this work, simultaneous generation of three types of laser induced periodic surface structure (LIPSS) on Zn have been demonstrated by processing it with the linearly polarized femtosecond (fs) laser pulses of 100 fs duration at wavelength 800 nm. Morphological characterization of the generated micro/nanostructures have been done by Field Emission Scanning Electron Microscopy (FESEM). In the Energy Dispersive X-ray (EDX) study, the Zn: O atomic ratio has been found to be 70%: 30% in the LIPSS containing region. In contrast to this, in region containing no LIPSS, the Zn: O atomic ratio have been found to be 90%: 10%. These observations indicate that by laser processing the not only LIPSS can be formed but their chemical composition can be altered. Investigation on highspeed surface micro/nano generation has also been done by optimizing laser and other experimental parameters. Similarly, we have done texturing on Ti surface with high scanning speeds (5mm/s, 10mm/s, 20mm/s) and studied the surface morphology. There is no good LIPSS found in case of 5mm/s and 20mm/s where as in case of 10mm/s good LIPSS generated. Also we systematically investigated the effect of scanning speed and laser pulse energy on width of line shaped Ti surface microstructures. It is observed that when the processing