Study of thermal behavior during the directed energy deposition (DED) of Ti6Al4V alloy using finite element modeling (FEM)

Abstract

Directed energy deposition (DED) offers the ability for a high deposition rate as compared to other additive manufacturing (AM) processes generally due to the high layer thickness compared to other AM processes. Finite element modeling (FEM) of a DED process can predict the melt-pool and temperature profile without extensive experimentation, thus saving considerable time, material and money. In the current study, FEM of a high layer thickness DED process is developed by considering the Gaussian heat source model to investigate the melt-pool and temperature profiles under different process conditions. The current model is in agreement with the experimental data. Results showed insufficient melting at the very start of the process, but complete melting is achieved as the process continues. From the 2nd layer onwards, there is partial remelting of previous layers. The model predicted a rise in temperature and melt-pool dimensions when the power increases and the opposite effect when the scan speed is increased. It showed the accurate implementation of the Gaussian distributed heat source model for a high-layer thickness DED model.