Finite Element Simulation and Experimental Verification of Selective Laser Melting Process of Ti-6Al-4V Lattice Structures

In order to investigate selective laser melting (SLM) processes of lattice structures, a finite element (FE) model concerning SLM forming process was established, which was employed to simulate the SLM process of Ti-6Al-4V lattice structure. First, Slic3r software was used to generate G-codes from CAD files, including hatch spacing, laser power, layer thickness, and scanning speed, which were then converted into a series of toolpath information and imported into the FE model to control the “element birth and death”, thus simulate the layer-by-layer deposition process of the SLM process. With this technique, the printed layers are activated one by one as the powders spread, and participate in the FE calculations. Based on the proposed FE model, a scanning path strategy adapted to the lattice structure was proposed and verified. The results show that as the forming height increases, the heat at the corner accumulates, leading to an increase in thermal stresses there and thereby aggravating the risk of rupture. Compared to the default strategy, the proposed optimized scanning strategy can reduce the stress concentration at the corner due to the decreased thermal accumulation of the part. Therefore, this study can provide optimization guidance for SLM process of metallic lattice components.