Effects of laser and scanning parameters on surface modification of MONEL® alloy 400 by picosecond laser

•A picosecond laser is employed in modifying the surface of MONEL® alloy 400 under four laser parameters.•Ripples, micro-grooves, micro-holes, and chaotic structures were formed.•The surface roughness Sa was in nanoscale except under high fluence.•Pulse overlap of 0.87 creates the surfaces with the lowest Sa.•The contact angle decreases as the hatching distance increases.•Surface free energies increase as the hatching distance increases.