Residual Stress of ۳۱۶L Samples Manufactured by Selective Laser Melting Method withConsideration of Evaporation

In the next few years, selective laser melting (SLM) islikely to become more important in industrialapplications. Various defects are present in a SLMmanufacturedpart, such as vaporization, un-meltedpowders, evaporation, and cracking. Evaporation has aneffect on the surface morphology and has a significantrole in defect and pore formation. Mechanical modelingof the defects’ formation can help to avoid certain ofthem by controlling process parameters. The currentstudy investigates the significance of includingevaporation in the stress analysis of SLM systems. Fivephases (powder, melting, mushy zone, solidified, andvapor phases) are considered, as well as the re-meltingof the previous layer due to the deposited next layer.The thermo-mechanical properties of all five phaseswere considered to be temperature-dependent. Anillustrative example is provided to show theapplicability of the method. In this regard, several userdefinedsubroutines were developed in Abaqus andStandard. The elements that experience temperatureshigher than the evaporation temperature were removedusing element deletion in Abaqus. The results revealedthat residual deformation stabilizes after the secondlayer and increases with the number of tracks, with thefirst track having the lowest residual deformation valuesand the fourth track having the greatest.

Keywords:

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