Deformation behavior modelling of lattice structures manufactured by a selective laser melting of 316L steel powder

Abstract

Research into the plastic deformation process in the lattice structure produced by selective laser melting (SLM) of powder from 316L austenitic stainless steel was carried out by compression tests along the build direction and perpendicular to it. The resulting stress–strain curve parameters showed anisotropic behaviour of such a structure. Differences in the crystallographic texture of both the bulk and lattice samples were also discovered, so the direct use of the mechanical properties of the bulk materials for calculation of lattice structure deformation behaviour would be incorrect. To overcome this limitation, the crystal plasticity finite element model based on the DAMASK framework was used, and the mechanical properties of the lattice structure material were calculated with respect to the crystallographic texture differences. In turn, the data obtained for the bulk material was used to model the plastic deformation of the lattice structure and these results are in good agreement with the experimental data. Therefore, it is possible to use the bulk material data for forecasting the lattice structure deformation. The resultant model allows for the prediction of the deformation behaviour of the lattice ribs.

Keywords

• Metallic lattice structure
• Selective laser melting
• 316L steel
• Plastic deformation
• Crystallographic texture
• Modelling