High-temperature phase transition behavior and magnetocaloric effect in a sub-rapidly solidified La–Fe–Si plate produced by centrifugal casting

摘要

A sub-rapidly solidified La Fe_(11.6)Si_(1.4)plate was fabricated directly from liquid by centrifugal casting method.The phase constitution,microstructure and magnetocaloric effect were investigated using backscatter scanning electron microscopy,X-ray diffraction,differential scanning calorimetry and physical property measurement system.When the plate was annealed at 1373 K,1 phase was formed by a solid-state peritectoid reaction.A first-order magnetic phase transition occurred in the vicinity of188 K,and the effective refrigeration capacities reached 203.5 J/kg and 209.7 J/kg in plates annealed for1 h and 3 h,respectively,under a magnetic field change of 3 T.It is suggested that centrifugal casting may become a new approach to prepare high-performance La–Fe–Si magnetocaloric plates for practical applications,which could largely accelerate the formation of 1 phase during high-temperature heat-treatment process due to refined and homogeneous honeycombed microstructure.