Comprehensive performance of a ball-milled La 0.5 Pr 0.5 Fe 11.4 Si 1.6 B 0.2 H y /Al magnetocaloric composite

Due to the hydrogen embrittlement effect, La(Fe,Si) 13 -based hydrides can only exist in powder form, which limits their practical application. In this work, ductile and thermally conductive Al metal was homogeneously mixed with La 0.5 Pr 0.5 Fe 11.4 Si 1.6 B 0.2 using the ball milling method. Then hydrogenation and compactness shaping of the magnetocaloric composites were performed in one step via a sintering process under high hydrogen pressure. As the Al content reached 9 wt.%, the La 0.5 Pr 0.5 Fe 11.4 Si 1.6 B 0.2 H y /Al composite showed the mechanical behavior of a ductile material with a yield strength of ∼ 44 MPa and an ultimate strength of 269 MPa accompanied by a pronounced improvement in thermal conductivity. Due to the ease of formation of Fe–Al–Si phases and the several micron and submicron sizes of the composite particles caused by ball milling process, the magnetic entropy change of the composites was substantially reduced to ∼ 1.2 J/kg⋅K–1.5 J/kg⋅K at 0 T–1.5 T.