采用复合电镀技术,在黄铜表面制备高硬度的Ni-P-α-Al2O3 纳米复合镀层,研究了阴极电流密度、纳米α-Al2O3 添加量、镀液pH 值、镀液温度和电镀时间对镀层硬度的影响。结果表明:当镀液温度为45℃,阴极电流密度为4A/dm2,镀液pH 值为4.0,电镀时间为40min,镀液中纳米α-Al2O3 的质量浓度为10g/L时,所得镀层均匀、细致、平滑,经适当热处理后,显微硬度可达到1332HV。

The high hardness Ni-P-α-Al2O3 nano-composite coatings were prepared on brass substrates with the composite electroplating technology. The effect of cathodic current density, nano-α-Al2O3 content, pH value of plating bath, temperature of plating bath and plating time on the hardness of coatng was studied. The results show that the optimization conditions are the temperature 45℃, the cathodic current density4 A/dm2, the pH value 4.0 of the bath, the time 40 min and nano-α-Al2O3 content 10g/L. Under these conditions, the coatings are uniform and smooth. After appropriately heating treatment, the microhardness achieves 1 332HV.