Improvement in mechanical and magnetocaloric properties of hot-pressed La(Fe,Si)13/La70Co30 composites by grain boundary engineering

作者：Zhong, X. C.^*; Peng, D. R.; Dong, X. T.; Huang, J. H.; Zhang, H.; Huang, Y. L.; Wu, S. M.; Yu, H. Y.; Qiu, W. Q.; Liu, Z. W.; Ramanujan, R. V.

来源：MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, 2021, 263: 114900.

DOI：10.1016/j.mseb.2020.114900

• LaFe11.6Si1.4/La70Co30 composites
• Mechanical properties
• Magnetocaloric effect
• Sintering
• Grain boundary engineering

Magnetocaloric composites La(Fe,Si)(13)/La70Co30 were fabricated by hot-pressing (HP) followed by annealing. With increasing La70Co30 binder content up to 16 wt%, the maximum compressive strength (sigma(bc))(max) improved dramatically from 63 to 352 MPa. However, the maximum magnetic entropy change (-Delta S-M)(max) decreased from 10.0 to 5.6 Jkg(-1)K(-1) because of the presence of non-magnetic La70Co30. After annealing at 1323 K for 4 h the (sigma(bc))(max) of HP + Annealed composites with up to 12 wt% La70Co30 doubled compared to HP samples. On the other hand, for a La70Co30 content of 16 wt%, the (sigma(bc))(max) of HP + Annealed composites decreased slightly compared to that of HP samples, due to reduced alpha-Fe content and much greater 1:13 phase content in HP + Annealed samples. Remarkably, the (-Delta S-M)(max) of HP + Annealed composites improved from 4.8 to 9.2 Jkg(-1)K(-1) (under 2 T), due to 1:13 phase recombination, after annealing at 1323 K for 4 h.

• 单位
  南阳理工学院; 南昌航空大学; 北京科技大学