Residual Stress of 316L Samples Manufactured by Selective Laser Melting Method with Consideration of Evaporation

In the next few years, selective laser melting (SLM) is expected to become increasingly important in industrial applications. However, SLM-manufactured parts often have various defects, such as vaporization, un-melted powders, evaporation, and cracking. Evaporation, in particular, can affect the surface morphology and play a significant role in defect and pore formation. To avoid these defects, mechanical modeling of their formation is necessary, which can be achieved by controlling process parameters. The current study investigates the significance of including evaporation in the stress analysis of SLM systems. To this end, five phases (powder, melting, mushy zone, solidified, and vapor phases) were considered, as well as the re-melting of the previous layer due to the deposited next layer. The thermo-mechanical properties of all five phases were considered to be temperature-dependent. An illustrative example is provided to show the applicability of the method. In this regard, several user-defined subroutines were developed in Abaqus and Standard. The elements that experience temperatures higher than the evaporation temperature were removed using element deletion in Abaqus. The results revealed that residual deformation stabilizes after the second layer and increases with the number of tracks, with the first track having the lowest residual deformation values and the fourth track having the greatest.

Residual Stress of 316L Samples Manufactured by Selective Laser Melting Method with Consideration of Evaporation Keywords:

Selective Laser Melting , Vaporization , Residual Stress , Pores Formation , Element Deletion