Simulation and experimental verification of crystalline polymer and direct metal selective laser sintering

A previously developed two-dimensional finite element simulation of the SLS of amorphous polymers has been extended to the study of crystalline polymers and metals. For crystalline polymers, three developments have been needed: the treatment of latent heat of melting, the modifying of a viscous densification law to allow for the crystalline fraction of material during melting and, to obtain agreement with experiments, a consideration of the absorption depth of CO2 laser radiation into the powder bed; but the two-dimensional treatment remains sufficient. For metals, a different densification law and three-dimensional modelling have been needed for agreement with experiments on stainless steel powder beds.