电沉积Ni-Co-W合金的微结构与软磁性能

Microstructure and Soft Magnetic Properties of Electrodeposited Ni-Co-W Alloys

采用电沉积方法,通过改变镀液的pH值,在Cu基体上分别制备出不同结构和成分的Ni-W和Ni-Co-W合金涂层。采用XRD、SEM、EDX分析涂层的结构和成分。对Ni-W、Ni-Co-W合金进行显微硬度测量及磁性测量,研究材料性能和微结构之间的关系。结果表明:pH值等于9时制备的Ni-Co-W合金结构是平均晶粒尺寸为5nm的纳米晶,其显微硬度达到最大;在pH值等于6时制备的Ni-Co-W合金得到最小矫顽力(=23×79.6A/m),Co的加入使Ni-W合金的软磁性能变好。

The Ni-W and Ni-Co-W alloys have been electrodeposited on copper substrates from a citrate bath. The effects of pH values on the microstructure, soft magnetic properties and mechanical behaviors of the electrodeposited alloys have been investigated by XRD, SEM, EDX, VSM and Vickers microhardness measurements. The results show that the pH value affects the microstructure of both of the alloys. The microstructure of the alloys shows an amorphous structure if the pH value is less than 9, and a nanocrystalline structure with average grain size of 5 nm at the pH value of 9. The Vickers microhardness of Ni-Co-W electrodeposits reaches 10.5 GPa in the case of nanocrystalline structure. The coercivity reaches the minimum of 23×79.6 A/m when the pH value is 6. The soft magnetic properties and microhardness of electrodeposited Ni-W alloys are improved by Co adding.