Predictive Simulation of Process Windows for Powder Bed Fusion Additive Manufacturing: Influence of the Powder Bulk Density

Materials

Matthias Markl¹  Carolin Körner¹  Vera E. Küng¹  Alexander M. Rausch¹  Christoph Pobel² 

[1] Chair of Materials Science and Engineering for Metals (WTM), Department of Materials Science and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Martensstr. 5, D-91058 Erlangen, Germany;Joint Institute of Advanced Materials and Processes (ZMP), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Dr.-Mack-Str. 81, D-90762 Fürth, Germany;

关键词: additive manufacturing;    selective electron beam melting;    numerical simulation;    Ti-6Al-4V;    porosity;    powder density;    Lattice Boltzmann Method;    defect statistics;    process map;   

DOI  :  10.3390/ma10101117

来源: DOAJ

【 摘 要 】

The resulting properties of parts fabricated by powder bed fusion additive manufacturing processes are determined by their porosity, local composition, and microstructure. The objective of this work is to examine the influence of the stochastic powder bed on the process window for dense parts by means of numerical simulation. The investigations demonstrate the unique capability of simulating macroscopic domains in the range of millimeters with a mesoscopic approach, which resolves the powder bed and the hydrodynamics of the melt pool. A simulated process window reveals the influence of the stochastic powder layer. The numerical results are verified with an experimental process window for selective electron beam-melted Ti-6Al-4V. Furthermore, the influence of the powder bulk density is investigated numerically. The simulations predict an increase in porosity and surface roughness for samples produced with lower powder bulk densities. Due to its higher probability for unfavorable powder arrangements, the process stability is also decreased. This shrinks the actual parameter range in a process window for producing dense parts.

【 授权许可】

Unknown