Abstract

In recent years, additive manufacturing (AM) processes, especially the laser-based powder bed fusion of metals (PBF-LB/M), have evolved from rapid prototyping to the production of end-use parts. During fabrication, PBF-LB/M parts experience repeated heating and cooling cycles, leading to residual stresses in the finished parts. In addition, the parts are often exposed to superposed mechanical and thermal loads during operation. Designers and AM engineers use sophisticated software tools like finite element analysis (FEA) to generate topology-optimized parts that are only feasible with AM processes. The success of the FEA depends on factors like the modeling assumptions and the quality of the material model. However, in commercially available FE software, heavily simplified material models are implemented to enable reasonable calculation times. The availability of temperature-dependent material properties is limited to low and medium temperatures and the constitutive relationships are simplified to bilinear elasto-plastic models, which cannot capture nonlinear material responses. Here, we show that the highly nonlinear behavior of AlSi10Mg observed in uniaxial tensile tests at temperatures up to 440 °C can be excellently described by a Chaboche nonlinear kinematic hardening material model. An FEA verification of the tensile tests matches the linear-elastic region of the stress–strain curves and the strain hardening in the range of the experimental scatter. The ultimate tensile strength, which drops from 470 MPa at room temperature to 15 MPa at 440 °C, can be reproduced in the simulation with errors of 0–4%.

URL

https://link.springer.com/chapter/10.1007/978-3-031-77403-4_11