Microstructural evolution, magnetocaloric effect, mechanical and thermal properties of hot-pressed LaFe11.6Si1.4/Ce2Co7 composites prepared using strip-cast master alloy flakes

LaFe composites were prepared using strip casting flakes (SC-flakes) and heat treated flakes (HT-flakes) by hot pressing, denoted as SC-HP and HT-HP, respectively. Subsequently, additional heat treatment was performed. The microstructure evolution, phase constitution, magnetocaloric and mechanical properties of these SC-HP and HT-HP samples over a large range of heat treatment temperatures and times were compared. Heat treatment at 1373 K for 12 h resulted in Ce and Co diffusion into La(Fe,Si) particles. An increase of T from 228 to 289 K and a large (-Delta Sincrease from 1.89 to 5.01 J kg(Delta H = 2 T) was observed in SC-HP samples. Combining hot pressing and heat treatment considerably reduces processing time. 90% of theoretical density, compressive strength greater than 450 MPa, large (-Delta S-M)(max) of similar to 4.73-5.01 J kg and good thermal conductivity (lambda) above 5.5 Wm were also achieved, suggesting the practical use of such heat treated composites with attractive magnetocaloric, mechanical and thermal properties.