On the origin of cracking in laser powder bed fusion processed LaCe(Fe,Mn,Si)13, and the impact of post-processing
On the origin of cracking in laser powder bed fusion processed LaCe(Fe,Mn,Si)13, and the impact of post-processing
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DOI：
10.1016/j.jallcom.2023.172017
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发表时间：
2023-12
影响因子：
6.2
通讯作者：
Kun Sun;Abd El-Moez A. Mohamed;Minki Jeong;J. Head;Emily Rose Lewis;Peter Ibrahim;Oliver Peter Brooks-Olive
中科院分区：
文献类型：
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作者：
Kun Sun;Abd El-Moez A. Mohamed;Minki Jeong;J. Head;Emily Rose Lewis;Peter Ibrahim;Oliver Peter Brooks-Olive
摘要 激光粉末床熔融（LPBF）打印的LaCe（Fe，Mn，Si）13磁热材料在磁制冷方面具有巨大的潜力。然而，LPBF 加工中的高裂纹和缺陷敏感性仍然限制了其应用。本研究优化了 LPBF 工艺参数以获得最佳致密块。体积能量密度条件E V= 250 J/mm 3 表现出最低的裂纹密度和孔隙率。揭示了不同裂纹和缺陷的行为和机制。由于较高的扫描速度和舱口间距而导致较低的能量密度参数集，导致形成缺乏融合。观察到的热裂纹归因于应力集中和稳定的液膜。由于富 La/Ce/Si 相的韧性较差，在制造 (AF) 样品的微观结构中观察到的固态裂纹是预料之中的。热处理和淬火增加了 AF 样品的磁热效应 (MCE)。当施加到 1 T 场时，热处理样品的最大磁熵变（Δ S max）在 294 K 时为− 3.68 Jkg− 1 K− 1。居里温度（T c）（施加0.01 T场时为298 K）和优异的MCE使该材料成为实现室温磁制冷的理想选择。
Abstract LaCe (Fe, Mn, Si) 13 magnetocaloric material printed by laser powder bed fusion (LPBF) has a huge potential for magnetic refrigeration. However, high crack and defect susceptibility in LPBF processing remains a limitation of its application. This study optimised the LPBF process parameters for optimally dense blocks. The volumetric energy density condition, E V= 250 J/mm 3, showed the lowest crack density and porosity fraction. The behaviour and mechanism of different cracks and defects were revealed. The lower energy density parameter sets, caused by higher scanning speeds and hatch spacing, lead to the formation of lack-of-fusions. The hot cracking observed was attributed to stress concentration and a stable liquid film. The solid-state cracks observed were expected in the microstructure of the as-fabricated (AF) sample due to the poor toughness of the La/Ce/Si-rich phases. Thermal heat treatment and quenching increased the magnetocaloric effect (MCE) of the AF sample. The maximum magnetic entropy change (∆ S max) of the heat-treated sample was− 3.68 Jkg− 1 K− 1 at 294 K, when applied to a 1 T field. The Curie temperature (T c)(298 K when applied 0.01 T field) and superior MCE make the material an ideal choice for realising room-temperature magnetic refrigeration.