Product Code: ICA11_504

Effects of Melt Pool Size on Transient and Residual Stress in DMD Process
Authors:
Hyung Min Chae, NSF Center for Lasers and Plasmas in Advanced Manufacturing, Department of Mechanical Engineering; Ann Arbor MI USA
Jyoti Mazumder, NSF Center for Lasers and Plasmas in Advanced Manufacturing, Department of Mechanical Engineering, University of Michigan at Ann Arbor; -
Presented at ICALEO 2011

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. The effects of the processing parameters on melt pool size and temperature field are investigated, and how the different thermal behaviors influence transient and residual stresses in DMD process is analyzed. Lastly, the techniques of controlling residual stress with altering processing conditions are discussed.