How to control the crystallization of metallic glasses during laser powder bed fusion? Towards part-specific 3D printing of in situ composites
Łukasz Żrodowski, Rafał Wróblewski, M. Leonowicz, Bartosz Morończyk, Tomasz Choma, Jakub Ciftci, Wojciech Święszkowski, Anna Dobkowska, Ewa Ura‐Bińczyk, Piotr Błyskun, Jakub Jaroszewicz, Agnieszka Krawczyńska, Krzysztof Kulikowski, Bartłomiej Wysocki, Tomasz Cetner, Grzegorz Moneta, Xiaopeng Li, Lang Yuan, Aleksandra Małachowska, R. Chulist, Cezary Żrodowski
Abstract
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.