Periodic nano-ripples structures fabricated on WC/Co based TiAlN coatings by femtosecond pulsed laser

AbstractPeriodic nano-ripples structures were fabricated by femtosecond laser scanning on WC/Co based TiAlN coatings. The surface morphology, ripples dimension and changes in the element content of samples irradiated with different processing parameters were analysed. The results show that the formation and quality of ripples are largely determined by pulse energy, scanning speed and scanning spacings. The 3 μJ pulse energy, 500 μm s−1 scanning speed and 5 μm scanning spacing induce best quality ripples on TiAlN films among all experimental conditions. The period of ripples formed on TiAlN films gradually increases with increasing pulse energy, scanning speed and scanning spacing, which is smaller than the laser wavelength. With the high pulse energy and low scanning speed, TiAlN films could be removed, and ripples with period of 480–600 nm are formed on cemented carbide substrates. Concentration and distribution of all constitutive elements in the irradiated area are gradually changed with increasing pul...