Filtern
Dokumenttyp
- Zeitschriftenartikel (2)
- Vortrag (1)
Sprache
- Englisch (3)
Schlagworte
- Heat accumulation (2)
- Additive manufacturing (1)
- FEM (1)
- Finite element method (1)
- In situ monitoring (1)
- Inter layer time (1)
- Inter-layer time (1)
- LPBF (1)
- Laser powder bed fusion (1)
- Process simulation (1)
Organisationseinheit der BAM
Eingeladener Vortrag
- nein (1)
Heat accumulation during laser powder bed fusion (LPBF) of metallic build parts can adversely affect their microstructure and mechanical properties. To study the heat accumulation during 316L steel based parts manufactured by LPBF, a finite element method (FEM) based numerical study is carried out. For the investigation, a computationally efficient FEM based model, where the whole layer is simultaneously exposed to a heat source, is used. The simulation results are compared with experimental results to validate the numerical model. While considering different influencing factors such as volumetric energy density (VED) and inter-layer time (ILT), the FEM model is shown to successfully simulate the process of heat accumulation during LPBF based manufacturing of a cuboidal shaped geometry. It is shown that ILT and VED have a significant effect on heat accumulation. The validated numerical model provides a good basis for the optimization of processing parameters and geometries for a future investigation of a reduction of heat accumulation effects. Furthermore, it can be used to quickly provide preheating boundary conditions for detailed investigations by different model approaches at a finer scale for future studies.
In this talk, a numerical study of the heat accumulation during LPBF based manufacturing of 316L steel parts is presented. For the simulation, a computationally efficient FEM model is used, where several layers are simultaneously exposed to a volumetric heat source. For the validation of the model, the temperature field from simulation is compared with emissivity-corrected temperature measurements, which are obtained using thermography during experiments.
Additively manufactured components are characterized by heterogeneous mechanical properties due to variations of the microstructure, flaws and residual stresses resulting from the inhomogeneous fabrication process. The large number of influencing factors poses a further challenge in understanding the correlation between material properties, process parameters and component geometry. Therefore, the qualification of components based on witness specimens produced within the same job is questionable. This work aims to present a new strategy for the characterization of PBF-LB/M components based on representative specimens. The key assumption is the feasibility of a transfer of the thermal history from a component to a specimen. It is assumed that similar material properties are determined for components and specimens produced adopting a similar thermal history. After the definition of a region of interest in the component, a combination of thermal analyses by means of finite elements and in-situ experimental determination of the thermal history through infrared thermography is used to produce test coupons with a similar thermal history. The effectiveness of the procedure is demonstrated on a pressure vessel for applications in the chemical industry.