Preparation method of cyanide-free zinc precipitator for aluminium alloy applied in aluminium hub plating

Abstract

The invention provides a preparation method of a cyanide-free zinc precipitator for aluminium alloy applied in aluminium hub plating. The cyanide-free zinc precipitator for aluminium alloy is mainly prepared from the following components: 350mL / L to 450mL / L of plating bath solution, 8mL / L to 12mL / L of regulator, 120mL / L to 130mL / L of replenisher and the balance of water. The plating bath solutionconsists of 0.5g / L to 2.0g / L of copper ions, 0.1g / L to 0.8g / L of iron ions, 0.8g / L to 3.0g / L of nickel ions, 8g / L to 16g / L of zinc ions and 40g / L to 150g / L of hydroxyl ions according to sodium hydroxide; the regulator is an aqueous solution which contains at least one component among sodium nitrate, sodium nitrite, 2-mercaptobenzimidazole, benzotriazole, 2-mercaptobenzothiazole, polyethylene glycol, sodium ethylhexyl sulfate, thiourea, 1,3-diethyl thiourea, carboxymethylcellulose sodium, L-methionine, dipyridyl and sulfosalicyclic acid, and the concentration of the regulator is 150g / L to 250g / L. The preparation method adopts a process which replaces cyanide with the polynary complex additive, the cyanide-free zinc precipitator for aluminium alloy does not contain cyanide or strong complexing agent, and is nontoxic and harmless, the wastewater treatment is simple, and the preparation method is a clean production process which is vigorously and compulsorily promoted in China at present.

Description

technical field [0001] The invention relates to a cyanide-free zinc precipitation agent, in particular to a production method of an aluminum alloy cyanide-free zinc precipitation agent applied in aluminum wheel hub electroplating. Background technique [0002] In the aluminum wheel hub electroplating, due to the existence of the natural oxide film on the surface of the aluminum wheel hub substrate, the bonding strength between the substrate and its surface coating is very poor. In order to solve this problem, zinc-immersion treatment is usually used. Zinc-immersion is the most convenient and economical method among various pre-plating methods for aluminum parts, and it is also the most widely used process in industry. The zinc layer is a good overcoating layer for electroplating and chemical plating. The Bondel method makes the zinc precipitation solution multi-alloyed, which changes the bonding force of the coating. At the same time, the zinc precipitation solution contain...

AI Technical Summary

Problems solved by technology

However, the cyanide zinc process is still used in the above-mentioned aluminum wheel hub electroplating process