Non-linear thermal model of the Direct Laser Melting Process considering the adhesion of the consolidated material to the substrate using a domain with discontinuous material properties

Abstract

In the Direct Laser Melting Process the distribution of the heat between the powder flow and the substrate plays a crucial role in the adhesion of the supplied material. Nevertheless, during the interaction between them, laser beam and powder flow with a given section, the growth of the consolidated material introduces a continuous change in the conditions of the process which makes it difficult to evaluate the effective amount of energy addressed to the substrate leading to an effective melting of it. The present study proposes a non-linear thermal model where the thermo-physical properties of the domain change dynamically according to the evolution of the geometry of the supplied material, as a function, in turn, of the powder flow and the process speed. Important aspects such as the influence of the process parameters, especially, the shielding associated to the powder flow, are evaluated as conditioning factors for a successful adhesion.