Effect of Interlayer Cooling Time, Constraint and Tool Path Strategy on Deformation of Large Components Made by Laser Metal Deposition with Wire

Featured Application: In the aerospace and tool and die industries, this technology has great potential to enable fabrication of near-net shape components with a high production rate and low material waste. This simulation work potentially applies to the prediction of distortion and residual stresses for large and complex Ti-6Al-4V aerospace components fabricated by a laser metal deposition with wire process. Furthermore, it can be extended to structural components, such as the excavator arm that has been reported in the literature. Laser metal deposition with wire (LMD-w) is a developing additive manufacturing (AM) technology that has a high deposition material rate and efficiency and is suitable for fabrication of large aerospace components. However, control of material properties, geometry, and residual stresses is needed before LMD-w technology can be widely adopted for the construction of critical structural components. In this study, we investigated the effect of interlayer cooling time, clamp constraints, and tool path strategy on part distortion and residual stresses in large-scale laser additive manufactured Ti-6Al-4V components using finite element method (FEM). The simulations were validated with the temperature and the distortion measurements obtained from a real LMD-w process. We found that a shorter interlayer cooling time, full clamping constraints on the build plates, and a bidirectional tool path with 180 degrees rotation minimized part distortion and residual stresses and resulted in symmetric stress distribution.