Electrochromism combined plating solution for aluminum alloy hub

Abstract

The invention discloses an electrochromism combined plating solution for an aluminum alloy hub. The electrochromism combined plating solution is characterized by being composed of an electronickelling plating solution, a pyrophosphate copper plating solution and an electrochromism plating solution; the electronickelling plating solution is prepared from 80-90 g / L of nickel sulfate, 0.8-0.9 mol / L of fluorine ions, 15-20 g / L of ammonium citrate and 1-3 g / L of sodium sulfate; the pyrophosphate copper plating solution is prepared from 65-75 g / L of copper pyrophosphate, 230-240 g / L of potassium pyrophosphate and 28-32 g / L of ammonium citrate; the electrochromism plating solution is prepared from 260-280 g / L of chromic anhydride, 1.5-2.5 g / L of sulfuric acid, 2.0-2.2 g / L of trivalent chromium, 0.01-0.03 mol / L of lauryl sodium sulfate and 15-25 g / L of sodium sulfate.

Description

technical field [0001] The invention relates to the technical field of electroplating, in particular to an aluminum alloy wheel hub electrochrome plating combined plating solution. Background technique [0002] Aluminum alloy has excellent properties such as light weight, high specific strength, shock resistance and shock absorption, and is considered to be an excellent substitute for steel wheels in the automotive industry. The application of aluminum alloy in the automobile industry can reduce the weight of automobiles, and is an effective way to reduce energy consumption and exhaust emissions. The wheel hub is one of the parts that account for the largest weight of the vehicle. Using aluminum alloy as the material for manufacturing the wheel hub can achieve the purpose of effectively reducing the weight of the vehicle. At present, wheels made of aluminum alloys have been widely used in automobiles. However, the chemical properties of aluminum alloy are very active, and ...

AI Technical Summary

Problems solved by technology

[0004] (1) The aluminum alloy cyanide pre-copper plating process uses highly toxic cyanide, which is harmful to human health and pollutes the environment

[0005] (2) After the aluminum alloy is dipped in zinc, it is directly electroplated in a pyrophosphate solution, which is prone to poor bonding between the copper coating and the aluminum alloy substrate.

Because the complexing ability of pyrophosphate ions to copper ions is poor, the potential difference between the aluminum alloy substrate and metallic copper is very large. When copper is electroplated in pyrophosphate solution, the substrate aluminum and copper ions undergo a violent substitution reaction, which makes the copper coating Decreased binding to the substrate

The compactness of the pre-plating layer is not enough, and the plated parts are corroded during acid copper plating