Contactless surface flattening of additive manufactured nickel-base alloy parts by ultra-short pulsed laser ablation

Abstract

Nickel-base alloy samples produced by selective laser melting (SLM) exhibit high surface roughness of 14.2 μm ±4.8 μm standard deviation at the sidewalls. Ultra-short pulsed (USP) laser ablation at a pulse duration of 10 ps is applied to reduce the surface roughness. This flattening method does not require a melting phase. The influence of the tilt angle and the orientation of the SLM layers on the surface topography of the sample is investigated. Orthogonal laser ablation of Ni-base alloy samples leads to irregular surface topography and exposure of sharp spikes. Surface flattening by laser ablation is demonstrated applying a tilt angle of 80° in combination with a projected pulse fluence of 0.21 J/cm². A significant influence of the tilt angle and SLM layer orientation on the surface roughness is observed.