Chemical nickel-plating method for ZM6 magnesium alloy

Abstract

The invention relates to a method for chemically plating nickel to a ZM6 magnesium alloy. The method comprises the steps of performing pretreatment on a magnesium alloy matrix before plating and then performing chemical nickel plating to deposit a chemical nickel-plating layer, wherein the pretreatment before plating comprises four steps, namely alkali washing, acid washing, acid etching and zinc dipping; and the chemical nickel-plating layer is obtained by adopting basic nickel carbonate serving as a main salt, sodium hypophosphite serving as a reducing agent, hydrofluoric acid serving as a corrosion inhibitor, lactic acid serving as a complexing agent and mixed solution of cadmium sulfate and potassium iodate serving as a brightening agent and a stabilizing agent. The bright and flat nickel-plating layer can be obtained by plating at the temperature of about 85 DEG C after the zinc dipping of a plated piece. The method is suitable for chemically plating the nickel to the ZM6 magnesium alloy material to achieve the aim of protecting the ZM6 magnesium alloy. The method has the advantages of high plating speed and good protection.

Description

technical field [0001] The invention relates to a ZM6 magnesium alloy electroless nickel plating method, which belongs to the technical field of metal corrosion and protection. Background technique [0002] Magnesium alloy has the lowest density among practical metal structural materials, at 1.74g / cm 3 , is 1 / 3 of steel and 2 / 3 of aluminum. Because of its lightness, high specific strength, good impact resistance, good electromagnetic shielding function, thermal conductivity, good electrical conductivity, and easy recycling, magnesium and its alloys have broad applications in the fields of national defense, transportation, and communications. application prospects. However, magnesium alloys have high chemical activity and are prone to corrosion failure, so their poor corrosion resistance restricts their further promotion and application. For this reason, magnesium alloys must be subjected to surface protection treatment before use. Among them, electroless nickel plating, ...

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Problems solved by technology

[0003] ZM6 (Mg-2.6Nd-0.6Zn-0.8Zr) alloy is a heat-resistant high-strength cast magnesium alloy, which is mainly used for housing parts such as casings and oil pump covers. However, there are few reports on its surface protection.

The pretreatment of magnesium alloy electroless nickel plating is greatly affected by the substrate, and the existing pretreatment methods can easily lead to problems such as peeling and slow plating speed of ZM6 magnesium alloy during electroless nickel plating. Therefore, it is necessary to find a suitable pretreatment method for ZM6 substrate. Subsequent electroless nickel plating is beneficial

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