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以纯铜棒为基体,采用复合电镀技术制备了Ni–Al2O3复合电极。镀液组成和工艺条件为:Ni SO4·6H2O 250~300 g/L,Ni Cl2·6H2O 40~50 g/L,Al2O3 10~60 g/L,H3BO3 35~40 g/L,十二烷基硫酸钠0.05 g/L,p H 3~4,阴极平均电流密度2~6 A/dm2,温度30~70°C,时间3 h。分析了镀液中Al2O3颗粒添加量、温度和阴极电流密度对Ni–Al2O3复合镀层Al2O3含量、均匀性和显微硬度的影响。分别以Ni–Al2O3复合电极和纯铜电极为工具,对W7Mo4Cr4V2Co5高速钢进行电火花加工(EDM)试验。在Al2O3添加量30 g/L、阴极电流密度3 A/dm2、温度50°C的条件下,所得镀层厚度为100μm,Al2O3颗粒体积分数为14.48%,显微硬度为434.72 HV,综合性能最佳。Ni–Al2O3复合电极在EDM试验中的相对质量损耗约为纯铜电极的1/5,抗电蚀性更优。
The pure copper rods as the matrix, the composite plating technology prepared Ni-Al2O3 composite electrode. The composition and process conditions of the bath are as follows: Ni SO4 6H2O 250-300 g / L, Ni Cl2 6H2O 40-50 g / L, Al2O3 10-60 g / L, H3BO3 35-40 g / L, dodecyl Sodium sulfate 0.05 g / L, p H 3 ~ 4, the average cathode current density of 2 ~ 6 A / dm2, temperature 30 ~ 70 ° C, time 3 h. The effects of Al2O3 particle addition, temperature and cathodic current density on the Al2O3 content, homogeneity and microhardness of Ni-Al2O3 composite coating were analyzed. The EDM tests of W7Mo4Cr4V2Co5 high speed steel were carried out by using Ni-Al2O3 composite electrode and pure copper electrode respectively. Under the condition of 30 g / L of Al2O3, 3 A / dm2 of cathode current density and 50 ° C of temperature, the obtained coating has a thickness of 100 μm, the volume fraction of Al2O3 particles is 14.48% and the microhardness is 434.72 HV, . The relative mass loss of Ni-Al2O3 composite electrode in EDM test is about 1/5 of that of pure copper electrode, and the electric erosion resistance is better.