Microstructure, magnetocaloric and mechanical properties of LaFe11.8Si1.2/Y64Co36 composites prepared by hot pressing and diffusion annealing

To elucidate the role of elements in the increase of 1:13 phase content in La-Fe-Si/RE-Co composites prepared by hot pressing and annealing, the diffusion behavior of Y and Co during annealing and their influence on the microstructure, magnetocaloric and mechanical properties of LaFe11.8Si1.2/ Y64Co36 composites were investigated. After annealing, Co atoms diffused into the LaFe11.8Si1.2 particles and stabilized the 1:13 phase. Y atoms reacted with Fe atoms to form the stable Y2Fe17-type phase, instead of diffusing into the 1:13 phase. As a result, the values of T-C and (-Delta S-M)(max) increased. A relatively large (- Delta S-M)(max) of 4.94 J/(kgK-.) (mu(0)Delta H = 2 T) at a T-C of similar to 223 K was observed. Y2Fe17-type phase bonded with the LaFe11.8Si1.2 particles, resulting in improved compressive strength (sigma(bc))(max) of 309 MPa for a Y64Co36 content of 10wt%.

Automated summary

To study the role of elements in the increase of 1:13 phase content in La-Fe-Si/RE-Co composites, the diffusion behavior of Y and Co during annealing and their influence on the microstructure, magnetocaloric and mechanical properties of LaFe11.8Si1.2/ Y64Co36 composites were investigated. The results showed that Co atoms diffused into the LaFe11.8Si1.2 particles and stabilized the 1:13 phase, while Y atoms reacted with Fe atoms to form the stable Y2Fe17-type phase, resulting in increased T-C and (-Delta S-M)(max) values. Additionally, the bonding between Y2Fe17-type phase and LaFe11.8Si1.2 particles improved the compressive strength (sigma(bc))(max) of the composites.