采用脉冲电沉积方法对三价铬电沉积Ni-Cr合金镀层工艺进行研究,确定并优化三价铬脉冲电沉积Ni-Cr合金的最佳镀液配方及工艺参数。研究镀液中各成分及工艺参数对三价铬脉冲电沉积Ni—Cr合金厚度及合金镀层中铬的影响,利用扫描电镜和电子能谱分析Ni-Cr合金镀层的形貌、微观结构和化学组成。结果表明,镀层厚度和Ni-Cr合金中铬含量在不同浓度的络合剂、稳定剂、乙酸钠及不同的电流密度、温度、pH值、占空比和脉冲频率下都存在极大值,且Ni-Cr合金厚度随合金中铬含量的增加而减少。当铬含量为24%时,镀层的厚度大于10μm,无裂纹,其晶粒为纳米球状晶粒。
The technology of pulse electrodeposition of nanocrystalline Ni-Cr alloy from trivalent chromium bath was studied. The optimum bath and operating conditions were obtained. The influences of the composition of the bath and the operating conditions on the thickness and the Cr contents of Ni-Cr plating layer were investigated. By SEM, EDS and XRD analyses, the morphology, microstructure and chemical composition were investigated. The results show that both the thickness of Ni-Cr plating layer and the contents of Cr have the maximum value under different concentration of complex agent, stabilizer, acetate and different temperature, current density, pH value, ratio of occupation and empty to pulse frequency, and the thickness decreases with the increase of Cr content. The thickness of the plating layer is above 10 μm and the crystal of chromium deposits with no-crackle is nanocrystalline when the content of Cr is 24 % (mass fraction).