NiTi形状记忆合金化学镀CoNiWP薄膜及磁性研究

Preparations and magnetic properties of CoNiWP films electrolessly deposited on NiTi shape memory alloy

采用化学镀法在NiTi形状记忆合金基体上镀覆CoNiWP磁性薄膜。用振动磁强计测试了样品的磁性能,结果表明NiTi形状记忆合金外层镀覆的金属薄膜是无定形结构并具有较好的磁性,其矫顽力是随化学镀进程逐渐增大到一定值后再逐渐下降。用扫描电镜表征镀层的形貌,结果表明化学镀开始初期,镀层颗粒比较细致,后来逐渐长大成晶胞状,当镀层完全覆盖基材后,再增加厚度会导致矫顽力下降。

Magnetic CoNiWP thin films were prepared by electroless deposition on NiTi shape memory alloy. The effects of electroless deposition time on the micrograph and the magnetic properties of films were investigated by SEM and VSM respectively. The results showed that the films are amorphous and have good magnetic properties. The grains of film were small （1-10μm） at the beginning, then grew up as big cell （10-40μm）. The coercivity Hc increased then decreased with the increasing of electroless deposition time.