Experimental and Numerical Analysis of Residual Stresses in Additive Layer Manufacturing by Laser Melting of Metal Powders

Determining the three-dimensional residual stress fields and the associated distortions using numerical simulations for multi-layered parts has proved to be a challenge in additive layer manufacturing. This paper presents an innovative three-dimensional thermal-elasto-plastic finite element model for predicting the deformation and residual stress fields in TiAl6V4 parts built on steel platforms. The developed model utilises temperature dependent material physical and mechanical properties as well as latent heat of melting. Experiments conducted using surface profilometry showed good agreement with the simulation results. The finite element model was used to investigate the overall effect of the melting powder on the platform deformation and residual stresses for multiple layers of deposited powder.