Analysis of thermal phenomena in LENS™ deposition

A two-dimensional finite element model was developed to calculate the temperature distribution for 316 stainless steel during the Laser Engineered Net Shaping (LENS™) rapid fabrication process as a function of time and process parameters. Numerical simulations are performed on the upper region of a thin plate part, where experimental data indicates that a uniform temperature can be assumed at the base of this region. The temperature at the base of the modeling region and the effective laser power are determined by matching predicted with previously measured temperature profiles surrounding the molten pool. Good agreement is obtained between the calculated and the measured temperature profiles. The model is then used to investigate the relative importance of physical properties and different mechanisms of heat transfer during the process. The results obtained in this work provide important and unavailable information on many thermal aspects of the LENS process.