STRESS FIELD MODEL FOR AN AlSi10Mg ALLOY FABRICATED BY SELECTIVE LASER MELTING (SLM)

Additive manufacturing has been established as a promising new fabrication technology, providing freeform freedom and production of engineering components with complex geometries not otherwise obtainable. Many investigations focus on the AlSi10Mg alloy, covering different aspects; for example: microstructure of the alloy, mechanical properties and residual stresses. However, a deeper understanding of the origin of the mechanical properties is still lacking. This investigation aims to correlate experimental work with a theoretical model that will provide a possible explanation for this issue. Based on our previous experimental work, a model was developed showing the stress fields of the Si particles and their effect on dislocation slip mechanisms along with a numerical calculation of the stress contribution. The Si particle distribution was determined through microstructural observation while focusing on the fine eutectic morphology. A single cellular cell comprised of an Al matrix in its center surrounded by individual Si particles served as the basic structure unit for the model. The results of the model were then compared to experimental mechanical testing for specimens that underwent the typical T5 treatment commonly performed on SLM-fabricated products.