Simulation of Volume Energy Density Effect on Roughness in Selective Laser Melting

Simulation of Volume Energy Density Effect on Roughness in Selective Laser Melting

Selective Laser Melting (SLM) is a manufacturing method in which the metal powder is used as a material, and a layer of powder is deposited with a roller and then melted with a high-energy laser beam to build each layer of a part. The product made by SLM has a density close to 100% of material. However, its performance in surface quality is not satisfactory. In this study, the finite element simulation software was used to analyze the manufacturing process parameters and temperature distribution in the single melting trajectory and multiple melting trajectories SLM process. The simulation results were compared with the experimental results to verify the influence of temperature distribution on surface roughness. In the single track simulation, the simulation results meet with the experimental results. At the same laser power, the faster the speed, the lower the energy density, and as the volumetric energy density decreases, the track width shrinks. In multiple track simulation, the temperature increases as the number of scan track increases until the maximum temperature, and the thermal accumulation effect is clearly observed in the temperature profile. It was found in the simulation results that when the maximum temperature is near the melting point of the metal, the surface quality of the specimen will be better. Therefore, controlling the temperature, that is, controlling the scanning speed and laser power, is very important when selecting a SLM process parameter.