Periodic and uniform nanogratings formed on cemented carbide by femtosecond laser scanning

SEM images of the nanogratings formed on the surface of YS8 cemented carbide by femtosecond laser pulses with different single pulse energies, (a) 2.75μJ, (b) 2.5μJ, (c) 2.25μJ, (d) 2μJ, (e) 1.75μJ, and (f) EDX composition analysis in the selected area point 1 of (a). P denotes the orientation of the laser beam polarization. S denotes the orientation of the laser scanning. (Scanning speed V=500μm/s, scanning spacing D=5μm). •Periodic and uniform nanogratings have been fabricated on cemented carbide.•Nanograting uniformity is largely determined by three factors in this research.•Nanograting period increases gradually with the decrease of single pulse energy.•Nanograting period increases gradually with the increase of scanning speed.•Nanograting period maintains a fixed value under different scanning spacings. Periodic and uniform nanogratings are fabricated by femtosecond laser scanning on cemented carbide. Specifically, three experiments are designed to study the influence of single pulse energy, scanning speed, and scanning spacing on the period and the uniformity of the formed nanogratings. The results show that the sample with single pulse energy of 2μJ, scanning speed of 1000μm/s, and scanning spacing of 5μm shows the best quality of nanogratings among all the tested samples at different processing parameters. The uniformity of the nanogratings is largely determined by single pulse energy, scanning speed, and scanning spacing. Single pulse energy and scanning speed significantly affect the period of the nanogratings, whereas the period of the nanogratings maintains a fixed value under different scanning spacings. The period of the nanogratings increases gradually with the decrease of the single pulse energy and the increase of the scanning speed, respectively.