复合粘结La_(0.8)Ce_(0.2)Fe_(11.7-x)Mn_(x)Si_(1.3)H_(1.8)磁工质的磁性能

Magnetic Properties of Mix-Bonded La_(0.8)Ce_(0.2)Fe_(11.7-x)Mn_(x)Si_(1.3)H_(1.8) Magnetic Refrigerants

采用中频感应炉制备La_(0.8)Ce_(0.2)Fe_(11.7-x)Mn_(x)Si_(1.3)母合金并退火,将合金饱和氢化后破碎成粉末。通过环氧树脂粘结,将居里温度T_(C)间隔为5 K的多种La_(0.8)Ce_(0.2)Fe_(11.7-x)Mn_(x)Si_(1.3)H_(1.8)(x=0.23,0.26,0.29,0.32,质量分数,%)合金粉末进行混合粘结,提高合金的磁熵半峰宽。用Versa Lab和绝热温变直接测量仪测试粘结样品的磁性能。结果表明,与单一成分粘结样品相比,混合粘结样品的最大等温磁熵变有所降低,磁熵半峰宽以及相对制冷能力有所提高。含4种成分的混合粘结样品的相对制冷能力可以达到139.2 J/kg。

La_(0.8)Ce_(0.2)Fe_(11.7-x)Mn_(x)Si_(1.3)master alloys were prepared by medium frequency induction furnace,then annealed,saturatedly hydrogenated,and finally crushed into powders.The multiple components of La_(0.8)Ce_(0.2)Fe_(11.7-x)MnxSi_(1.3)H_(1.8)(x=0.23,0.26,0.29,0.32,wt%) powders with the Curie temperature(T_(C)) interval of 5 K were mix-bonded by epoxy resin to extend the full width at half maximum of magnetic entropy of alloy.The magnetic properties of the mix-bonded specimens were measured by Versa Lab and adiabatic temperature change direct test device.The maximal magnetic entropy change of the mix-bonded specimens is decreased,whereas the full width at half maximum of magnetic entropy and the relative cooling power are increased,compared with those of the single-component-bonded specimens.The maximal relative cooling power is 139.2 J/kg for the four-component-bonded specimen.