Superior properties of LaFe11.8Si1.2/La65Co35 magnetocaloric composites processed by spark plasma sintering

A series of LaFe11.8Si1.2/La65Co35 bulk composites were fabricated by spark plasma sintering (SPS) followed by diffusion annealing. The effect of sintering temperature (1073-1223 K) on the magnetocaloric and other properties of LaFe11.8Si1.2/La65Co35 bulk composites were investigated. The 1:13 phase content in all the annealed samples was similar to 90 wt%. The mechanical and magnetocaloric properties of these annealed bulk composites could be improved by tuning the sintering temperature. The Curie temperature (T-C) and maximum magnetic entropy change (-Delta S-M)(max) of the annealed samples varied in the range of 211-228 K and 5.56-9.33 J kg(-1) K-1, respectively. Selected samples exhibited excellent mechanical and magnetocaloric properties. The (-Delta S-M)(max) value was 9.33 J kg(-1) K-1 at TC of 217.8 K. Its maximum compressive strength (sigma(bc))(max) value was 540 MPa at a strain of 3.48%, which exceeded the mechanical properties of most LaeFeeSi based bulk composites prepared by hot- pressing sintering (HPS). Thus, LaeFeeSi based bulk composites with good comprehensive properties could be obtained by combining SPS and diffusion annealing. (c) 2022 The Author(s). Published by Elsevier B.V.