3D-Printed heterostructured gradient stainless steel obtained by laser-powder bed fusion
This project focuses on the fabrication of heterostructured 316L stainless steel components using Laser Powder Bed Fusion (LPBF). To establish reference properties, homogeneous samples were first produced using different sets of parameters (laser power, scan speed, hatch spacing and layer thickness)...
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| Formato: | tesis de maestría |
| Fecha de publicación: | 2026 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:dnet:upcommonspor::16c9ff88f8e6d0ab406d4d89d7a5e557 |
| Acesso em linha: | https://hdl.handle.net/2117/462040 |
| Access Level: | acceso abierto |
| Palavra-chave: | Additive manufacturing Stainless steel Lasers -- Industrial applications Sintering Heterosctructured stainless steel Laser Powder Bed Fusion Fabricació additiva Acer inoxidable Materials heteroestructurats Làsers -- Aplicacions industrials Sinterització Àrees temàtiques de la UPC::Enginyeria dels materials |
| Resumo: | This project focuses on the fabrication of heterostructured 316L stainless steel components using Laser Powder Bed Fusion (LPBF). To establish reference properties, homogeneous samples were first produced using different sets of parameters (laser power, scan speed, hatch spacing and layer thickness) allowing characterization of baseline porosity and hardness. The investigated samples exhibited Vickers microhardness values in the range of 236–273 HV0.05, while porosity was generally low, between approximately 0.11% and 0.5%. These results guided the design of heterostructured samples. Heterogeneous components were manufactured using alternating and graded layering strategies, where layers printed with different energy densities were combined within a single part. The goal of these structures is to create controlled variations in microstructure along the building direction, enabling local tuning of mechanical properties. Hardness measurements across the thickness showed that heterostructuring can lead to slightly higher or more uniform hardness compared with homogeneous references. Porosity analysis revealed that even layers normally prone to higher porosity remained well consolidated when incorporated into a heterostructured sample, indicating that layer-to-layer thermal interactions and partial remelting improve powder densification and reduce defects. Tensile testing across all architectures showed yield strengths ranging from approximately 250 to 520 MPa, ultimate tensile strengths of 300–620 MPa, and fracture strains ranging from 0.05 to 0.30. These findings highlight the potential of heterostructuring in LPBF to tailor microstructure and mechanical performance in stainless steel parts. By strategically combining printing parameters within a single component, it is possible to enhance local hardness, maintain low porosity, and produce more reliable and high-performance additively manufactured metallic parts. |
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