Influence on microstructure, strength and ductility of build platform temperature during laser powder bed fusion of AlSi10Mg
(2020) Acta Materialia — Vol. 201, p. 231-243 (2020)
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- Authors
- Abstract
- AlSi10Mg manufactured by laser powder bed fusion (or selective laser melting) benefits from a very fine microstructure that imparts significant mechanical strength to the material compared to the cast alloy. The build platform temperature stands out as a significant processing parameter influencing the microstructure as it affects the cooling rate and thermal gradient during manufacturing. Setting the build platform temperature to 200°C yields a negligible residual stress level. However, the strength is lower compared to that obtained using a build platform temperature of 35°C, with a similar fracture strain. A detailed 3D microstructural analysis involving focused ion beam/scanning electron microscopy tomography was performed to describe the connectivity and size of the Si-rich eutectic network and link it to the strength and fracture strain. The coarser microstructure of the 200°C build platform material is more prone to damage. The α-Al cells as well as the Si-rich precipitates present a larger size in the 200°C material, the latter thus having a lower strengthening effect. The Si-rich eutectic network is also less interconnected and has a larger thickness in the 200°C material. An analytical model is developed to exploit these microstructural features and predict the strength of the two materials.
- Affiliations
Université de Lyon Mateis, INSA Lyon Huazhong University of Science and Technology Department of Mechanics Hubei Key Laboratory of Engineering Structural Analysis and Safety Assessment
Citations
Santos Macias, J. G., Douillard, T., Zhao, L., Maire, E., Pyka, G., & Simar, A. (2020). Influence on microstructure, strength and ductility of build platform temperature during laser powder bed fusion of AlSi10Mg. Acta Materialia, 201, 231-243. https://doi.org/10.1016/j.actamat.2020.10.001 (Original work published 2020)