Mechanical and magnetocaloric properties of La(Fe,Mn,Si)13Hδ/Cu plates prepared by Cu-binding prior to hydrogenation

Abstract

La(Fe,Si)13Hδ hydrides with large magnetocaloric effect (MCE) have been demonstrated as promising magnetic refrigerants around room temperature. To meet the shape requirements in a refrigerator, hot-pressing technique was usually employed. However, hydrogenation prior to hot-pressing is inappropriate sometimes because the dehydrogenation occurs at about 450 K, and the incorporation of large amount of metal as binder often makes the MCE reduce a lot. Here, we report a new way to prepare the metal-bonded LaFe11.4Mn0.3Si1.3Hδ hydride plates as thin as 0.5 mm by metal-binding prior to hydrogenation instead. By adding a small amount 4 wt% of Cu, LaFe11.4Mn0.3Si1.3/Cu plates were firstly prepared. Afterwards, hydrogen absorption can be still conducted because lots of holes and naked surfaces still left, which favor hydrogen atoms into lattice. As a result, saturated hydrogenation can be achieved. The MCE keeps large, and good mechanical properties and thermal conductivity have been demonstrated.