采用环氧树脂粘结Sm0.88Nd0.12Fe1.93合金颗粒,在外磁场中固化成型制备了磁致伸缩复合材料,研究了不同磁场中成型复合材料的显微组织、磁致伸缩和电阻率。结果表明,成型磁场为0T时,复合体系为0-3型构型,合金颗粒在树脂基体中无序分布;施加0.6T的固化磁场,获得伪1-3型构型复合材料,合金颗粒趋近定向排列。Sm0.88Nd0.12Fe1.93合金颗粒体积分数为30%、固化磁场为0.6T时,制备的复合材料在1.3T磁场下的磁致伸缩系数(λ∥–λ⊥)可达–1088×10-6,为铸态合金磁致伸缩系数的86.6%。相同颗粒体积分数的粘结Sm0.88Nd0.12Fe1.93复合材料,固化磁场为0.6T较无固化磁场条件下的电阻率降低85%。
Magnetostrictive composites were prepared by mixing Sm0.88Nd0.12Fe1.93 alloy particles with epoxy resin and curing under an external magnetic field. The microstructure, magnetostriction and electrical resistivity of bonded Sm0.88Nd0.12Fe1.93 composites prepared at different external magnetic fields were investigated. Results show that the maximum magnetostriction λ∥–λ⊥ at 1.3 T reaches –1088×10-6 for the bonded composites with 30% (volume fraction) Sm0.88Nd0.12Fe1.93 particles cured under 0.6 T, which is 86.6% of the magnetostriction for the as-cast alloy. Compared with the as-cast Sm0.88Nd0.12Fe1.93 alloy, electrical resistivity of the epoxy-bonded Sm0.88Nd0.12Fe1.93 composites prepared under 0.6 T is 6 orders of magnitude higher. Additionally, electrical resistivity for the composites cured under 0 field is higher than that cured under 0.6 T, which might be related to the alignment of SmNdFe powders.