Correlations of Interlayer Time with Distortion of Large Ti-6Al-4V Components in Laser Metal Deposition with Wire

Laser metal deposition with wire (LMD-w) is one of the emerging additive manufacturing (AM) technologies for large-scale aerospace components due to high deposition rates and material efficiency. However, it often results in undesired stresses and distortions due to non-uniform expansion and contraction of material during printing. Controlling inter-layer time, preheating, and clamping are the effective methods to mitigate the thermally induced stress and deformation. In this study, the effect of inter-layer cooling time on part distortion is investigated using a finite element method (FEM). The model accounts for actual tool paths, power, and cooling conditions. The results show that the model effectively captures the fluctuation of the Ti-6Al-4V plate during printing. Also, it shows an asymmetric distortion on the plate edges. Ultimately, the sequentially coupled thermal-stress simulation provided a quantitative understanding of the inter-layer cooling time on titanium plate distortion for the large-scale LMD-w process.