三元配位体系对低磷复合化学镀镍-磷-纳米二氧化钛的影响

Effect of Ternary Complex System on Low Phosphorus Composite Electroless Nickel-Phosphorus-Nano-Titania

低磷复合化学镀镍层具有优异的耐碱腐蚀性和超高的硬度,但尚未应用到规模化生产中。以沉积速率、镀层磷含量、硬度及孔隙率为评价指标,在乳酸-丙酸二元配位剂的基础上,分别研究了采用三乙醇胺、苹果酸、丁二酸、乙二胺作为辅助配位剂时对低磷复合化学镀镍-磷-纳米二氧化钛的影响。镀液的基础配方和工艺条件为:NaH_(2)PO_(2)·H_(2)O_(2)3 g/L,NiSO_(4)·6H_(2)O_(2)8 g/L,辅助配位剂适量,乳酸18 mL/L,丙酸4 mL/L,CH 3 COONa·3H_(2)O 15 g/L,十二烷基苯磺酸钠(SDBS)40 mg/L,pH值4.8±0.2,温度(85±2)℃,施镀时间1 h。结果表明:采用乙二胺作为辅助配位剂时,镀层的综合性能良好。当乙二胺的用量为4 mL/L时,镀速为23.62μm/h,镀层磷含量为3.53%,镀层镀态硬度为561.4 HV,孔隙率为0.35个/cm 2。

The low phosphorus composite electroless nickel layer has excellent alkali corrosion resistance and ultra-high hardness,but it has not been applied to large-scale production.Based on the evaluation indexes of deposition rate,phosphorus content,hardness and porosity of the coating,and on the basis of lactic acid-propionic acid binary complexing agent,the influences of triethanolamine,malic acid,succinic acid,and ethylenediamine as auxiliary complexing agents on the low phosphorus composite electroless nickel-phosphorus-nano-titania were studied.The basic formula and process conditions of the plating solution were:23 g/L NaH_(2)PO_(2)·H_(2)O,28 g/L NiSO_(4)·6H_(2)O,appropriate amount of auxiliary complexing agent,18 mL/L lactic acid,4 mL/L propionic acid,15 g/L CH 3 COONa·3H_(2)O,40 mg/L sodium dodecylbenzene sulfonate(SDBS),pH value 4.8±0.2,temperature(85±2)℃and 1 h of plating time.Results showed that when ethylenediamine was used as the auxiliary complexing agent,the overall performance of the coating was excellent.When the amount of ethylenediamine was 4 mL/L and the plating speed was 23.62μm/h,the as-obtained coating had 3.53%of phosphorus content,561.4 HV of the plating hardness and 0.35 pieces/cm 2 of porosity.