Numerical investigation and an effective predicting system on the Selective Laser Melting (SLM) process with Ti6Al4V alloy

Selective laser melting (SLM) is a powder bed based modern additive manufacturing process which is widely used to make full-density complex parts in a layer upon layer fashion. However, the high temperature in heating and fast cooling during SLM process result in the large tensile residual stress which affects to the quality of the SLM printed part such as part distortion and cracks. This study proposes to develop a system for predicting the quality of the printed part from the manufacturing planning to remove the failures before carrying out the real printing process. For developing such system, a three-dimensional (3D) finite element model with moving volumetric heat source has performed to predict the surface temperature distribution and the molten pool size of Ti6AL4V. From this model, interrelationship between process parameters and temperature distribution has derived out. Based on that, the deformation has predicted through calculating residual stress along with the result of temperature distribution to minimise or eliminate deformation and residual stresses and strains.