Powder sheet additive manufacturing of multi-material structures: experimental and computational characterizations
Selective laser melting (SLM) of multi-material structures (MMS) is of significance because it allows for bespoke structural innovation and high-accuracy process tailoring. However, most of the currently developed loose powder-based SLM techniques for MMS are limited by the long changeover time and...
| Autores: | , , , , , , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/407184 |
| Acesso em linha: | https://hdl.handle.net/2117/407184 https://dx.doi.org/10.1016/j.compositesb.2024.111203 |
| Access Level: | acceso abierto |
| Palavra-chave: | Manufacturing processes -- Mathematical models Powder sheet additive manufacturing Multi-material structures Manufacturability Defect control Thermo-mechanical simulation Fabricació -- Models matemàtics Àrees temàtiques de la UPC::Enginyeria dels materials |
| Resumo: | Selective laser melting (SLM) of multi-material structures (MMS) is of significance because it allows for bespoke structural innovation and high-accuracy process tailoring. However, most of the currently developed loose powder-based SLM techniques for MMS are limited by the long changeover time and potential cross-contamination between materials. To address these issues, a novel Metal Additive Manufacturing using Powder Sheets (MAPS) technique is proposed for printing MMS within a single process. It utilizes flexible powder sheets as the feedstock material, which are composed of metal powder-polymer binder composites. The printability of MMS by MAPS is assessed through the fabrication of three-phase SS304-IN718-SS304 composites with increased geometric dimensions on the SS316 baseplates. The effects of part size on the evolution of the melt-pool morphology and the formation of defects during MAPS are investigated by experimental characterizations and computational modeling. The results show that when fabricating larger MMS, the use of a longer scan-vector easily leads to defects such as lack-of-fusion porosity, balling and cracks. This is due to the longer duration of inter-hatch cooling time, the reduced amount of thermal accumulation and the higher degree of residual stresses. By adopting an island scanning strategy, a defect-free large-size MMS with variations of chemical composition, microstructure and microhardness is successfully printed by MAPS. The proposed MAPS method offers a new solution for producing high-quality MMS. |
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