Temmler, A.A.TemmlerPirch, N.N.Pirch2022-03-062022-03-062020https://publica.fraunhofer.de/handle/publica/26356310.1016/j.apsusc.2020.146393Conventional surface structuring processes often share two crucial disadvantages. Firstly, an additional surface finishing is usually required. Secondly, excess material is wasted. In contrast, during laser remelting, a redistribution of material can be achieved that results in a structured surface with a low micro-roughness. Therefore, this investigation focuses on the mechanism of surface structure formation during laser remelting on the hot work steel H11. A newly developed FEM-model is introduced and surface structure formation is investigated specifically for a sinusoidal modulation of laser power. A fiber coupled Nd:YAG laser was used to emit laser radiation with a focal beam diameter of 250 µm and laser power between 15 W and 215 W. At a scanning speed of 50 mm/s, the structuring of wavelengths from 0.25 mm to 4 mm was investigated. After one process step, structure heights of up to 12 µm were achieved for single tracks. In addition, the theoretical model revealed that melt pool changes lead to a deformation of the melt pool surface, which results in the formation of surface structures. Furthermore, the agreement between simulations and experiments indicates that the Marangoni-convection has only a minor impact on surface structure formation during laser remelting.en621669journal article