Ultrafast Laser Ablation of Inconel 718 for Surface Improvement

Abstract

Inconel 718 is considered difficult to machine because of its ability to maintain its properties at high temperatures. The low thermal conductivity of the alloy causes accelerated tool deterioration when machining. Selective laser melting (SLM) additive manufacturing introduces a possibility of eliminating these difficulties, and producing complex shapes with this difficult-to-machine material. However, high surface roughness and porosity usually occur at the surface of components produced through additive manufacturing. In this study, the surfaces of Inconel 718 samples produced through selective laser melting were treated using laser ablation. The process parameters for the laser ablation process were analyzed in order to achieve a minimum surface roughness. The surfaces of the samples were observed after printing and after the laser ablation process using a microscope and the roughness average was measured using a profilometer. Optimized process parameters were achieved, and have the capability to reduce the surface roughness to a minimum Ra of 3.024 µm.