Finite element analysis of temperature distribution in single metallic powder layer during metal laser sintering

The metal laser sintering (MLS) is used to make strong or hard metallic models for tools and dies directly from metallic powders. Thermal distortion is the serious problem after cooling of the solidified part rapidly. Uncontrolled temperature distribution in the metallic powder layer leads to thermal distortion of the solidified part. The study of temperature distribution within the metallic layer during NILS is important from the quality of the layer point of view. The high temperature generated in the powder layer leads to thermal distortion of the part and causes thermal as well as residual stresses in the part. In this paper the powder layer is assumed to be subjected to plane stress type of temperature variation and a transient finite element method-based thermal model has been developed to calculate the temperature distribution within a single metallic layer during MLS. A finite element code has been developed and validated with the known results from the literature. The obtained results of temperature distribution show the temperature and temperature gradient variation along X- and Y-axis. The effect of process parameters such as laser power, beam diameter, laser on-time, laser off-time and hatch spacing on temperature distribution within a model made of titanium during NILS is studied. The results computed by the present model agree with experimental results. Temperature increases with increase in laser power and laser on-time but temperature decreases with increase in laser off-time and hatch spacing. (c) 2006 Elsevier Ltd. All rights reserved.