Numerical modeling of the thermal behavior and residual stress in the direct metal laser sintering process of titanium alloy products

In this paper the heat transfer and residual stress evolution in the direct metal laser sintering process of the additive manufacturing of titanium alloy products are studied. A numerical model is developed in a COMSOL multiphysics environment considering the temperature-dependent material properties of TiAl6V4. The thermo-mechanical coupled simulation is performed. 3-D simulation is used to study single layer laser sintering. A 2-D model is used to study the multi-layer effects of additive manufacturing. The results reveal the behavior of the melt pool size, temperature history, and change of the residual stresses of a single layer and among the multiple layers of the effects of the change of the local base temperature and laser power etc. The result of the simulation provides a better understanding of the complex thermo-mechanical mechanisms of laser sintering additive manufacturing processes. (C) 2017 Elsevier B.V. All rights reserved.