How to control the crystallization of metallic glasses during laser powder bed fusion? Towards part-specific 3D printing of in situ composites

• Published in: Additive manufacturing Vol. 76; p. 103775
• Main Authors: Żrodowski, Łukasz, Wróblewski, Rafał, Leonowicz, Marcin, Morończyk, Bartosz, Choma, Tomasz, Ciftci, Jakub, Święszkowski, Wojciech, Dobkowska, Anna, Ura-Bińczyk, Ewa, Błyskun, Piotr, Jaroszewicz, Jakub, Krawczyńska, Agnieszka, Kulikowski, Krzysztof, Wysocki, Bartłomiej, Cetner, Tomasz, Moneta, Grzegorz, Li, Xiaopeng, Yuan, Lang, Małachowska, Aleksandra, Chulist, Robert, Żrodowski, Cezary
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25-08-2023
• Subjects: Bulk metallic glasses (BMGs); Crystallization, 4D-printing; Laser powder bed fusion (LPBF); Selective laser melting (SLM), in situ composites; Selective laser melting (SLM), in situ composites; Crystallization, 4D-printing; Laser powder bed fusion (LPBF); Bulk metallic glasses (BMGs)
• ISSN: 2214-8604; 2214-7810
• DOI: 10.1016/j.addma.2023.103775

This paper describes a strategy for creating highly oriented crystalline-amorphous composites using the laser powder bed fusion (LPBF) process. The strategy involves using a novel two-stage melting approach and ultra-high-pressure hot isostatic pressing (HIP) on well-known AMZ4 (Zr59.3Cu28.8Al10.4Nb1.5) and equiatomic CuZr amorphous alloys.
The experiments demonstrate that by the fine-tuning laser parameters, allowed to obtain parts with purely amorphous material and to create geometry-specific microstructural design composites based on laminate amorphous-crystalline structure. This approach also provides novel opportunities for nonequilibrium phase distribution design by controlling local crystallization in the heat-affected zone (HAZ) and avoiding heat accumulation. Additionally, the porous amorphous material can be densified without crystallization using HIP at a temperature near the supercooled liquid region.
The distribution of the crystalline phase created during LPBF and crystallization on pre-induced nuclei during HIP was proven to be a critical factor for composite properties. Wear and bending tests reveal the influence of crystalline-amorphous layers orientation on mechanical properties. The functional demonstrators were manufactured to show the possibilities in the design for additive manufacturing (DfAM) with a microstructure-designed composites.
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