Finite element modelling for part distortion calculation in selective laser melting

Abstract Additive manufacturing (AM) is presently a strong candidate for automotive, medical and aerospace applications. The present work focuses on the influence of laser scanning speed on part distortion, when depositing AISI 304 stainless steel using selective laser melting (SLM). The commercial software ABAQUS was used to develop a 3D finite element model to simulate the deposition process and predict thermal gradients and part distortion. The user subroutine USDFLD was used to model powder to solid phase transformation, and the laser beam effects were modelled using the user subroutine DFLUX. In addition, heat convection within the molten pool was considered by enhancing the thermal conductivity of molten material. Also, the element birth technique was used to simulate material deposition of successive layers. The predicted results were validated by comparing them to the available literature, where a good match was found. It was concluded that higher laser scanning speeds results in lower surface temperatures and higher vertical deflections. In addition, the effect of scanning speed on temperature gradients and part distortion was found to be more evident by the deposition of subsequent layers.