Thermal and mechanical finite element modeling of laser forming from metal and ceramic powders

A 3D thermomechanical finite element model including the effect of the powder-to-solid transition has been developed to investigate the transient temperature, transient stresses, residual stresses and warpage of the component made of multiple materials produced using a laser-assisted layer-by-layer fabrication approach. The model encompasses the effects of the temperature- and porosity-dependent thermal conduction and radiation as well as the temperature-dependent natural convection. It is found that changing from the initial solid elements to powder elements results in higher temperature gradients, larger transient and residual stresses, and increased warpage. Mechanisms responsible for these phenomena are discussed based on heat transfer capabilities and constraints resulting from different initial materials.