Prediction of Bulk Residual Stresses in Electron Beam Additive Manfuactured Aluminium Alloy

CSIRO is actively involved in Additive Manufacturing (AM), primarily of titanium-based alloys and has been conducting an industrially sponsored project on predicting distortion and residual stresses in some of these processes. This has resulted in a predictive tool called C-THRU^TM. In this paper we employ C-THRU^TM to predict residual stress development in a T-shaped build of aluminium alloy AA 2319 on a substrate of alloy AA 2219 by Electron Beam Additive Manufacturing. The model predictions of the residual stresses are compared with those measured by neutron diffraction on experimental builds produced at NASA-Langley and reported by Brice and Hofmeister (Metallurgical and Materials Transactions A, published on line:29 June 2013). It was found that the predicted residual stresses in the longitudinal and vertical directions were in very good agreement with experiments, whereas those in the transverse direction followed the trend of experiments but slightly shifted to the tensile region. The influence of the thermal and mechanical properties of the materials and material constitutive models on result variations is also discussed.