Effects of melt pool size on transient and residual stress in DMD process

Abstract

A self-consistent transient 3D model is developed to predict thermal behavior in Direct Metal Deposition (DMD) process, and the obtained results from the numerical model are used to predict transient and residual stresses with a commercial software package ABAQUS. Temperature field and stress formation during the DMD process determine residual stress that is directly related to fracture and fatigue behavior of the products. The convection in melt pool influences the overall heat and solute transfer during the process, and the fluid flow determines temperature profile at the solidification front. Therefore, residual stress distribution can be altered by different melt pool geometry with different processing variables such as laser power and scanning speed. In this study, we first perform an investigation of how the residual stress in DMD process is developed with time. The laser power is then varied to examine the effects of the power on thermal behavior such as melt pool size and temperature field. Lastly, we analysed how thermal behaviors with different laser power change the residual stress.A self-consistent transient 3D model is developed to predict thermal behavior in Direct Metal Deposition (DMD) process, and the obtained results from the numerical model are used to predict transient and residual stresses with a commercial software package ABAQUS. Temperature field and stress formation during the DMD process determine residual stress that is directly related to fracture and fatigue behavior of the products. The convection in melt pool influences the overall heat and solute transfer during the process, and the fluid flow determines temperature profile at the solidification front. Therefore, residual stress distribution can be altered by different melt pool geometry with different processing variables such as laser power and scanning speed. In this study, we first perform an investigation of how the residual stress in DMD process is developed with time. The laser power is then varied to examine the effects of the power on thermal behavior such as melt pool size and temperature field. Lastly...