Phase constitution, microstructure evolution and magnetocaloric properties of LaFe11.8Si1.2 strip-casting flakes

The phase composition, microstructural evolution and magnetocaloric properties of LaFe11.8S1.2 strip-casting flakes annealed at different temperatures and annealing times were investigated. The phase constitution and microstructure of strip-casting flakes are sensitive to annealing temperature, 1373K was found to be the optimum temperature for 1:13 phase formation. The microstructure and magnetocaloric properties changed with annealing time due to the diffusion of Fe and Si atoms. Samples annealed at 1373K for 10h reveal a high content (89.40 wt%) of the 1:13 phase and exhibited a maximum entropy change (-Delta S-M)(max) of 16.89J/(kg.K) at 187K. These annealed LaFe11.8S1.2 strip-casting flakes are ideal master alloys for powder metallurgy fabrication of the heat exchangers used inactive magnetic regenerator prototypes.

Automated summary

The study focused on the phase composition, microstructural evolution, and magnetocaloric properties of LaFe11.8S1.2 strip-casting flakes annealed at different temperatures and times. An optimal temperature of 1373K was determined for the formation of the 1:13 phase, while the maximum magnetic entropy change was observed in samples annealed for 10 hours at this temperature.