ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Influence of porosity on plasticity and damage of SLM manufactured metal assessed by a micromechanical modeling scheme

Date: 22.09.2020
Time: 15:00
Place: Materials Science and Engineering Congress 2020 online conference TU Darmstadt, Germany, online conference

Mahesh Ramaswamy Guru Prasad
Abhishek Biswas
Napat Vajragupta
Alexander Hartmaier

The versatility and the ease of fabrication offered by additive manufacturing (AM) has made it an indispensable technique for processing complex three-dimensional parts of metallic components. However, the generated microstructures show a high degree of complexity due to the complex solidification process of the melt pool. The characterized microstructure comprises elongated grains and defects, like pores and micro-cracks, whose presence is detrimental as they act as precursors for failure. In this study, micromechanical modeling is applied to gain deeper insight into the influence of defects on plasticity and damage of 316L stainless steel specimens produced by selective laser melting (SLM). In the first step, a synthetic microstructure is generated from the statistical data obtained from microstructure characterization. The synthetic microstructure is then used with a non-local crystal plasticity (CP) model for finite element analysis. A damage model is implemented in the non-local CP framework, to model anisotropic mechanical behavior including damage evolution. Numerical simulations show that the shape of the pores not only affects the yielding and hardening behavior, but also influences the porosity evolution. In the absence of the shape effect, the anisotropic behavior during material softening caused by crystallographic orientations surrounding the pores is also captured by the proposed approach.

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