Details

Autor(en) / Beteiligte

• Soderlind, Julie
• Martin, Aiden A.
• Calta, Nicholas P.
• DePond, Philip J.
• Wang, Jenny
• Vrancken, Bey
• Schäublin, Robin E.
• Basu, Indranil
• Thampy, Vivek
• Fong, Anthony Y.
• Kiss, Andrew M.
• Berry, Joel M.
• Perron, Aurélien
• Nelson Weker, Johanna
• Stone, Kevin H.
• Tassone, Christopher J.
• Toney, Michael F.
• Van Buuren, Anthony
• Löffler, Jörg F.
• Risbud, Subhash H.
• Matthews, Manyalibo J.

Titel

Melt-Pool Dynamics and Microstructure of Mg Alloy WE43 under Laser Powder Bed Fusion Additive Manufacturing Conditions

Ist Teil von

• Crystals (Basel), 2022-10, Vol.12 (10), p.1437

Ort / Verlag

Basel: MDPI AG

Erscheinungsjahr

2022

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Magnesium-based alloy WE43 is a state-of-the-art bioresorbable metallic implant material. There is a need for implants with both complex geometries to match the mechanical properties of bone and refined microstructure for controlled resorption. Additive manufacturing (AM) using laser powder bed fusion (LPBF) presents a viable fabrication method for implant applications, as it offers near-net-shape geometrical control, allows for geometry customization based on an individual patient, and fast cooling rates to achieve a refined microstructure. In this study, the laser–alloy interaction is investigated over a range of LPBF-relevant processing conditions to reveal melt-pool dynamics, pore formation, and the microstructure of laser-melted WE43. In situ X-ray imaging reveals distinct laser-induced vapor depression morphology regimes, with minimal pore formation at laser-scan speeds greater than 500 mm/s. Optical and electron microscopy of cross-sectioned laser tracks reveal three distinct microstructural regimes that can be controlled by adjusting laser-scan parameters: columnar, dendritic, and banded microstructures. These regimes are consistent with those predicted by the analytic solidification theory for conduction-mode welding, but not for keyhole-mode tracks. The results provide insight into the fundamental laser–material interactions of the WE43 alloy under AM-processing conditions and are critical for the successful implementation of LPBF-produced WE43 parts in biomedical applications.