First-order phase transition La-Fe-Si bulk materials with small hysteresis by laser powder bed fusion: Microstructure and magnetocaloric effect

Authors：Lu, Xiang; Miao, Liya; Zhang, Yifei; Wang, Zhi; Zhang, Hu; Li, Guowei; Liu, Jian^*

Source：Scripta Materialia, 2023, 232: 115479.

DOI：10.1016/j.scriptamat.2023.115479

• Laser powder bed fusion
• La-Fe-Si alloys
• Microstructure
• Magnetocaloric effect

In this study, laser powder bed fusion method is used to fabricate first-order phase transition LaFe13.9Si1.4 bulk materials. The main finding is that a negligible hysteresis is obtained after annealing. We attribute this primarily to the numerous refined alpha-Fe residual phase which promotes the paramagnetic/ferromagnetic phase transition by the stray field at the interface. The fine microstructure and amorphous/nanocrystalline La-rich phase in the as-printed sample contribute to the formation of the refined alpha-Fe phases accompanied by a large alpha-Fe/La(Fe, Si)13 interface during annealing. More importantly, the first-order phase transition behavior is maintained and the magnetic entropy change for 0-2 T is 13.4 J/kg K. This study demonstrates that laser powder bed fusion is a feasible approach for fabricating high-performance rare-earth-based magnetic materials.

• Institution
  中国科学院研究生院; 北京科技大学; 上海大学; 中国科学院宁波材料技术与工程研究所