Experimental and Numerical Study of the LENS Rapid Fabrication Process

Several aspects of the thermal behavior of deposited stainless steel 410 (SS410) during the laser engineered net shaping (LENS (TM)) process were investigated experimentally and numerically. Thermal images in the molten pool and surrounding area were recorded using a two-wavelength imaging pyrometer system, and analyzed using THERMAVIZ (TM) software to obtain the temperature distribution. The molten pool size, temperature gradient, and cooling rate were obtained from the recorded history of temperature profiles. The dynamic shape of the molten pool, including the pool size in both travel direction and depth direction was investigated, and the effect of different process parameters was illustrated. The thermal experiments were performed in a LENS (TM) 850 machine with a 3 kW IPG Photonics laser for different process parameters. A three-dimensional finite element model was developed to calculate the temperature distribution in the LENS (TM) process as a function of time and process parameters. The modeling results showed good agreement with the experimental data.