Study of residual stress in selective laser melting of Ti6Al4V

Selective laser melting (SLM) produces a large amount of residual stress which limits its applicability. Despite the increasing number of studies to understand the relationship between the process parameters and the residual stress, the underlying complex mechanisms are yet to be understood. In this work, a 3D finite element model (FEM) is established to investigate the relationship between the process parameters and the residual stress during SLM. When the process parameters are in different ranges, the residual stress behavior is different. The complex relationship between the residual stress and the process parameters could be the reason for the contradictory parametric effects reported in the literature. The magnitude of the parametric effect on the residual stress is obtained. The influence of the scanning speed is stronger than that of the laser power, which is in turn stronger than that of the hatch spacing. These results can bring insights into the understanding of the residual stress during SLM. [Display omitted] •The stress generation and evolution are investigated through the temperature and stress history during SLM.•The evolution of the stress can be divided into four areas. The residual stress is decided by the four stages.•When the process parameters are in different range, the residual stress behavior is different.•The magnitude of the parametric effect on the residual stress is scanning speed > laser power > hatch spacing.