Analysis of residual stress formation in additive manufacturing of Ti-6Al-4V

Laser Beam Melting (LBM) and Additive Metal Deposition (AMD) offer many advantages such as high freedom in design and short lead times. Although Ti-6Al-4V is one of the most widely used materials in powder bed-based LBM and the nozzle-fed powder-based AMD, the occurrence of residual stresses is still a common cause for failure of parts or even the entire build job. In this paper, the influence of different exposure patterns on the residual stresses is shown. A simulation-based approach is chosen to develop a strategy for further optimization of the exposure. For validation, X-ray diffraction and Crack Compliance Method have successfully been used in first experiments to determine the local distribution of residual stresses for both technologies. The results show a significant variation of the residual stresses.