pH值对中温化学镀镍-磷的影响

The Effects of pH Value on the Middle-temperature Electroless Nickel-phosphorus Plating Process

化学镀镍-磷技术作为表面强化的一种途径,已经得到越来越广泛的应用和不断的发展。为了研究pH值对镀层性能的影响,采用中温化学镀镍工艺,以醋酸钠为缓冲剂,以乳酸为络合剂,在酸性体系中化学沉积镍-磷合金。研究了溶液的pH值对化学镀镍-磷合金的沉积速度、镀层性能的影响。结果表明:pH值对镀速的影响较大,随着pH值的升高,镀速逐渐增加,镀层磷含量逐渐降低;在一定范围内硬度和腐蚀速度随pH值的升高而增加,在pH值为5.1时,镀层的综合性能达到最好。

As a means of surface hardening, the technique of chemical nickel-phosphate plating has been extensively and continuously developed. In order to researeh the effect of pH value to properties on coating, on the base of middle-temperature electroless nickel-phosphorus alloy technique, Ni-P alloy has been electrolessly deposited from a acid bath containing sodium acetate as a paregoric and lactic acid and another acid as compound complexing agent. The effect of operating condition, pH value on the deposition rate and properties of coating of electroless nickel-phosphorus alloy technique was studied. The result shows that the pH value influences deposition rate remarkably, the deposition rate increases and the content of phosphorus reduces with the increasing of pH value ; in certain extent, hardness and corrosion rate increase with the increasing of pH value, and when the pH value is 5.1, the integrated properties of coating is best in the present work.