酸洗对钕铁硼磁体电镀镍层防护失效的影响

Effect of Pickling on Adhesion Failure of Ni-coating on Sintered NdFeB Substrate

摘要:

研究了酸洗工艺对电镀镍镀层与烧结钕铁硼基体间结合强度的影响。结果表明：经过酸洗之后，钕铁硼基体表面层变成了疏松结构，表面的显微硬度降低，镍镀层与钕铁硼基体结合强度随酸洗时间的增加而逐渐降低。通过分析剥离层的横截面发现，镀层与基体的剥离面位于钕铁硼基体内部，而不是镀层与基体的结合界面。采用垂直拉伸的剥离方法测量结合强度，表面和断面形貌通过SEM进行观察，利用维氏硬度计测量钕铁硼经过酸洗后的表面维氏硬度。

Abstract:

In order to understand the adhesion failure between Ni-coating and sintered NdFeB substrate, the effect of pickling process on the adhesion strength of Ni-coating on NdFeB substrate was studied. The results reveal that the pickling leads to the formation of loose structure on NdFeB surface and the reduction of micro-hardness of NdFeB surface. The adhesion strength of Ni-coating on NdFeB substrate declines gradually with the increasing time of pickling. It can be found from the cross section morphology of stripped layer that the adhesion failure occurs in inner NdFeB substrate close to the surface, rather than in the interface between Ni-coating and NdFeB substrate.