Formation method of nickel-tungsten alloy coating

Abstract

The invention relates to a method for forming a nickel-tungsten alloy coating, comprising the following steps: placing a workpiece to be plated and an anode material into an electroplating solution for electroplating, so as to form a nickel-tungsten alloy coating on the surface of the workpiece; the electroplating solution includes the following components: nickel Salt, tungstate, complexing agent and anode stabilizer; the complexing agent is selected from citric acid and / or citrate; the anode stabilizer is an enamine compound. The invention discloses a method for forming a nickel-tungsten alloy coating that can not only prolong the service life of an electroplating solution, but also form a dense and bright coating on a workpiece.

Description

technical field [0001] The invention relates to the technical field of electroplating, in particular to a method for forming a nickel-tungsten alloy plating layer. Background technique [0002] The chrome layer formed by hard chrome plating has high hardness and high wear resistance, and can maintain good stability and gloss in long-term storage. However, the method of hard chrome plating has several disadvantages, such as high current density, low current efficiency and high energy cost during the electroplating process, and also, the uniformity of the final formed chrome layer is poor. Hexavalent chromium is also toxic, and chromium salts escape in the form of mist or through the discharge of wastewater, which will cause great harm to the environment and human health. There is an urgent need to develop a non-toxic, corrosion- and wear-resistant alternative to chromium plating. [0003] Nickel-tungsten alloy coating, as one of the substitutes for chromium coating, is wide...

AI Technical Summary

Problems solved by technology

However, the method of hard chromium plating has many disadvantages, such as high current density, low current efficiency and high energy cost during the electroplating process, and the final chromium plating layer has poor uniformity

Hexavalent chromium is also toxic, and chromium salts escape in the form of mist or through wastewater discharge, which will cause great harm to the environment and human health

On the one hand, it causes a large consumption of citrate ions; on the other hand, it decomposes to produce some short-chain molecules, which makes the color of the electroplating solution darker, thus seriously affecting the life of the electroplating solution

Activated carbon cannot completely absorb the decomposition products of citrate ions in the plating solution

In the prior art, most nickel-tungsten alloy plating solutions must be scrapped after being energized at 500KAh / L, and the service life of nickel-tungsten alloy plating solutions is very short