Effect of single and multiple parts manufacturing on temperature-induced residual stress problems in SLM

Abstract

In this study, the effects of the single and multiple productions of samples by additive manufacturing on residual stress and displacement (distortions) were investigated. The samples were manufactured by Selective Laser Melting (SLM) machine using Ti6Al4V powders. Each time a different number (1, 5 and 13 samples) of cubic shaped samples were produced on the building platform. During the process, samples were observed with a thermal camera first, in order to understand the relationship amongst the residual stress, displacement and temperature gradients. Then, displacement values were measured experimentally with Coordinate Measurement Machine (CMM) device. Next, both displacement and residual stresses were calculated via Finite Element Analysis (FEA) method. Finally, residual stresses and displacement equations were determined by genetic expressional programming (GEP) using the results and data obtained from the tests and FEA. According to the results, the regression values of residual stress and displacement equation were found to be 0.96% and 0.88%, respectively. As the number of manufactured samples on the same platform increased, temperatures and irregular temperature distribution were increased.