Metal additive manufacturing processes such as directed energy deposition process (DED), can be used to manufacture high value metal parts, with improved mechanical properties and efficiency. However, parts produced by DED can suffer from excessive temperature gradients, and heat accumulation due to the deposition process. The purpose of this study was to investigate the impact of the deposited area on thermos-mechanical characteristics for the case of deposition of Inconel 718 powder, on the AISI 1045 substrate, using the DED process through finite element analyses (FEAs). Nine types of FE models were developed. Temperature dependent cooling conditions were analyzed, and applied to the model. Laser heat source was defined, as the three-dimensional volumetric heat source based on the Gaussian distribution model. Temperature dependent properties were assigned to the models. The influence of the width and the length of the deposited region, on residual stress distributions in the vicinity of deposited region were investigated. Additionally, the impacts of the deposited area on deformation characteristics were examined.

Heat transfer characteristics in the vicinity of irradiated region of the beam of a selective laser melting (SLM) process affect the creation of the melted region during the deposition. The creation of the molten pool is greatly influenced by laser parameters and powder characteristics. The goal of the paper is to investigate the influence of laser parameters and powder porosity on thermal characteristics in the vicinity of the molten pool of the SLM process through repeated finite element analyses (FEAs). The power and the scan speed are chosen as the laser parameters. The laser is assumed to be a volumetric Gaussian heat flux model. Materials of the powder and the substrate are chosen as SUS17-4PH and S45C, respectively. Temperature dependent thermal properties for those material are used to perform the FEA. An appropriate efficiency of the heat flux is predicted by comparing the results of FEAs and those of experiments. The influence of laser parameters on temperature distributions in the vicinity of the melted region and the formation of the molten pool is examined. In addition, the effects of porosity of powders on heat transfer characteristics in the vicinity of the melted region are discussed.