Hydroxylated nano closed treatment liquid as well as preparation method and application thereof

Abstract

The invention relates to a hydroxylated nano closed treatment liquid as well as a preparation method and application thereof. The hydroxylated nano closed treatment liquid is prepared by mixing, according to a certain volume ratio, an inorganic basic component solution with the concentration being 5-30 wt%, a nanosol solution with the concentration being 3-20 wt%, a hydroxyl surfactant solution with the concentration being 0.1-5 wt% and an organic acid solution with the concentration being 10-40 wt%. According to the treatment liquid, between chemical nickel-plating and electroplating zinc-nickel plating layers, hydroxylated nano closed treatment is adopted, so that the corrosion resistance of the chemical nickel-plating layer, and the combined force with the subsequent zinc-nickel alloy plating layer are improved, and the percent of pass of electroplated products is improved to 98% or above from 70-80%. In the aspect of improving the corrosion resistance of automobile parts, the endurance in a salt-spray corrosion test is prolonged from the past 48 hours to 360 hours, and the corrosion resistance is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of electroplating, and in particular relates to a hydroxylated nano-encapsulation treatment liquid and a preparation method and application thereof. Background technique [0002] Under the trend of lightweight automobiles, some high-strength steel sheets and thin-walled parts have been widely used to reduce the weight of automobile parts, but high corrosion resistance is required. Plating protective coatings on the surface of parts is a common anti-rust method, such as electroplating corrosion-resistant coatings. However, for some narrow and complex parts, it is very difficult to uniformly form a sufficient thickness of coating by electroplating. For example, the interior of some high-strength oil supply thin tubes is narrow and complicated, and requires complete protective coating coverage. From the basic theory of electrodeposition and the distribution of electric lines, it can be known that thin tubes (s...

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Problems solved by technology

However, the bonding force between the coatings obtained in this way will be unstable and will be quickly passivated in the air after acid activation, making process control difficult

After the activation solution is used for a period of time, the activation effect will become worse, resulting in poor bonding between the electroless plating layer and the electroplating layer on the surface of the part

[0003] In summary, there are two important problems in thin tube electroless plating + electroplating: 1. There is only an electroless plating layer with pores inside the thin tube, and the corrosion resistance cannot meet the requirements of more than 360 hours (the thin tube is cut according to the national standard GB / T24195 Carry out the test, 96 hours); 2. The defective rate of binding force of the zinc-nickel alloy coating on the surface of the electroless coating can be electroplated inside the thin tube, reaching about 20%.