Residual stress in additively manufactured Inconel cubes; Selective Laser Melting versus Electron Beam Melting and a comparison of modelling techniques

Direct comparisons are made between the crystallographic texture and residual stress distribution within two otherwise identical Inconel cubes produced by Selective Laser Melting (SLM) and Electron Beam Melting (EBM) additive manufacturing processes. In both respects, significant differences were observed; the SLM process produced a sample with high residual stress and cubic texture, while the EBM process generated negligible residual stress and a fibre texture. In the case of the SLM sample, the paper continues on to examine two different approaches to modelling the residual stress field; 1. a simplistic version based on an assumed radially symmetric isotropic eigenstrain, and 2. a layer-by-layer combined thermo-mechanical approach based on finite element modelling. Both models were able to capture the important overall features of the residual stress distribution, however the layer-by-layer approach showed more fidelity in the finer details. •Residual stress and crystallographic texture from two 3D printing processes for inconel-718 samples are compared (SLM vs EBM).•Significant residual stresses up to yield are observed from SLM while EBM produced no detectable residual stress.•SLM and EBM produced very different texture; ‘Goss’ texture in the SLM sample, fibre texture in the EBM sample.•Two residual stress modelling approaches were compared; 1. An empirical model, and 2. A mechanistic layer-by-layer approach.•Both models captured the overall distribution of stress; the layer-by-layer showed more fidelity to small details.