稀土La对化学沉积Co-Ni-B合金镀层成分和性能的影响

Influences of rare earth La on the components and properties of electroless Co-Ni-B alloy film

研究了镀液中La的质量浓度对化学沉积Co-Ni-B-La合金镀层各组分质量分数以及合金镀层显微硬度的影响。比较了化学沉积Co-Ni-B合金镀层与化学沉积Co-Ni-B-La合金镀层的磁化强度、剩余磁化强度和矫顽力。结果表明:随着镀液中La的质量浓度的增加,化学沉积Co-Ni-B-La合金镀层中Co和La的质量分数呈现先增后降的趋势,在ρ(La)为0.8g/L时达到最大值,分别为91.46%和0.31%;而Ni和B的质量分数则随ρ(La)浓度的增大而呈现先减后增的趋势,在ρ(La)为0.8g/L时达到最小值,分别为4.59%和3.64%。合金镀层的显微硬度随着镀层中稀土含量的增加而增大,在ρ(La)为0.8g/L时,显微硬度达到最大值,为605HV。两种镀层的磁化强度对比表明,稀土能够提高镀层的饱和磁化强度,降低剩余磁化强度和矫顽力,故含La镀层显示出良好的软磁性能。

Influences of the mass concentration of La in the bath on the mass fraction of various components and microhardness of Co-Ni-B-La alloy film were studied. The magnetization intensity, residual magnetization intensity and coercitive force of electroless Co-Ni-B and Co-Ni-B-La alloy films were compared. The results show that mass fraction of Co and La of the electroless Co-Ni-B-La alloy film are increased firstly and then decreased, and the mass fraction of Ni and B are decreased firstly and then increased with increasing La mass concentration in the bath. The mass fraction of Co and La reached the largest values of 91.46% and 0.31% respectively, and the mass fraction of Ni and B reached the lowest values of 4.59% and 3.64% respectively at ρ（La）of 0.8 g/L. The micmhardness increases with increasing rare earth content of alloy film, and the micmhardness reaches the largest of 605 HV at to （La）of 0. 8 g/L. A eomparision of magnetization intensity between two deposits shows that the deposit containing La has favorable soft magnetization because rare earth can increase saturation magnetization intensity and decrease residual magnetization intensity and eoereitive force of Co-Ni-B-La alloy film.