Thermal study of a cladding layer of Inconel 625 in Directed Energy Deposition (DED) process using a phase-field model

Abstract

In an effort to simulate the involved thermal physical effects that occur in direct energy deposition (DED) a thermodynamically-consistent of phase-field method is developed. Two state parameters, characterizing phase change and consolidation, are used to allocate the proper material properties to each phase. The numerical transient solution is obtained via a finite element analysis. A set of experiments for single tracks scanning were carried out to provide dimensional data of the deposited cladding lines. By relying on a regression analytical formulation to establish the link between process parameters and geometries of deposited layers from experiments, an activation of passive elements in the finite element discretization is considered. The single-track cladding of Inconel 625 powder on tempered steel 42CrMo4 was printed with different power, scanning speed and feed-rate to assess their effect on the morphology of the melt pool and the solidification cooling rate. The predicted dimensions of melt pools were compared with experiments reported in the literature. In addition, this research correlated the used process parameter in the modelling of localized transient thermal with solidification parameters, namely, the thermal gradient (𝐺) and the solidification rate (𝑅).

Damage Evolution Simulations via a Coupled Crystal Plasticity and Cohesive Zone Model for Additively Manufactured Austenitic SS 316L DED Components

“…Energy density is widely used as a metric when designing processing parameters for additive manufacturing or expressing properties of additively manufactured materials, which can be defined as laser power, P, over the product of laser scan speed, v, and the hatch space, h, and layer thickness t, i.e., ED = P/(vht), with unit of J/m 3 [40]. The same group of authors proved in another numerical study that increasing the scanning speed leads to a smaller melt pool, while increasing laser power induces the bigger melt pool [26]. Thus, by increasing the energy density, the size of the melt pool expands where this process commonly leads to parts with enhanced material properties.…”

“…They studied the effect of the material interface on the mechanical response of the produced parts experimentally. The same group of authors [26] studied the effect of processing parameters on the melt pool size throughout the highfidelity process modelling for DED. They focused on the correlation of the melt pool size with the G-R response related to solidification and grain structures.…”