Kagathara Jwalant, Wieland Sandra, Gärtner Eric, Uhlenwinkel Volker, Steinbacher Matthias
Leibniz Institute for Materials Engineering-IWT, Badgasteiner Straße 3, 28359 Bremen, Germany.
Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Wiener Straße 12, 28359 Bremen, Germany.
Materials (Basel). 2020 Feb 7;13(3):773. doi: 10.3390/ma13030773.
In recent years, magnetocaloric materials have been extensively studied as materials for use in alternative cooling systems. Shaping the magnetocaloric material to thin-walled heat exchanger structures is an important step to achieve efficient magnetocaloric cooling systems. In the present work, experimental investigations were carried out on the heat treatment of LaFeSiCo alloy processed by Laser Beam Melting (LBM) technology. Due to the rapid solidification after melting, LBM results in a refined micro structure, which requires much shorter heat treatment to achieve a high percentage of magnetocaloric 1:13 phase compared to conventional cast material. The influence of the heat treatment parameters (temperature, time, and cooling rate) on the resulting microstructure has been extensively studied. In addition to the conventional heat treatment process, induction technology was investigated and the results were very promising in terms of achieving good magnetocaloric properties after short-time annealing. After only 15 min holding time at 1373 K, the magnetic entropy change (∆S) of -7.9 J/kg/K (0-2 T) was achieved.
近年来，磁热材料作为用于替代冷却系统的材料受到了广泛研究。将磁热材料加工成薄壁热交换器结构是实现高效磁热冷却系统的重要一步。在本工作中，对通过激光束熔化（LBM）技术加工的LaFeSiCo合金的热处理进行了实验研究。由于熔化后的快速凝固，LBM导致微观结构细化，与传统铸造材料相比，实现高百分比的磁热1:13相所需的热处理时间要短得多。已经广泛研究了热处理参数（温度、时间和冷却速率）对所得微观结构的影响。除了传统的热处理工艺外，还研究了感应技术，结果表明在短时间退火后实现良好的磁热性能方面非常有前景。在1373 K下仅保持15分钟后，就实现了-7.9 J/kg/K（0-2 T）的磁熵变（∆S）。
