Specifications

The published specifications for electroless nickel-phosphorus currently available in the United States include:

• AMS 2404, Electroless Nickel Plating (Ref 51)

• ASTM B 656, Autocatalytic Nickel Deposition on Metals for Engineering Use (Ref 43)

• Military Specification Requirements for Electroless Nickel Coatings (Ref 52)

In addition, an international standard has been drafted by the International Standards Organization (Ref 50). Published standards for electroless nickel-boron coatings for engineering purposes are not available.

Although these standards are good guidelines for testing and quality control, none include any real requirements for structural quality, corrosion resistance, or wear resistance. The standards consist primarily of a visual examination and simple tests for thickness and adhesion. Often this forces industrial users to develop their own internal specifications for coating quality. These in-house specifications can be relatively simple with requirements for only a few desired properties, or very detailed with requirements for substrate pretreatment, bath operation, equipment design, deposit chemistry, and properties.

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