Experimental investigation on surface structuring by laser remelting (WaveShape) on Inconel 718 using varying laser beam diameters and scan speeds

Conventional surface-structuring processes often share two crucial disadvantages. Firstly, an additional surface finishing is needed and secondly, these structuring processes are based on the removal and thus result in the waste of material. This work focusses on an experimental investigation of surface structuring by laser melting (WaveShape) on Inconel 718, a process in which surface structures are mainly created by reallocation of molten material. Circular laser beam diameters of 125 mu m, 250 um, and 500 mu m with a top-hat shaped intensity distribution, and scan speeds in the range of 25 mm/s to 200 mm/s were investigated for a sinusoidal modulation of laser power between 20 W and 365 W. Structure heights of up to 15 mu m were achieved on single tracks after one process step and up to 75 mu m after multi-pass processing. Areal surface structuring was demonstrated for wave and burling structures. Based on a process map generated from single track experiments, the achieved structure height for areal structuring could be predicted with sufficient accuracy. The results show that WaveShape is well suited to controllably create a variety of surface structures on Inconel 718.