Brass, a commonly used substrate for the deposition of electroless nickel, requires special consideration to achieve a suitable coating.
Brass Affects Adhesion Early
The natural oxide layer on the surface of the Brass can cause problems with adhesion of the deposit if it has not been removed prior to coating. The pre-treatment of the Brass can be a simple process of acid activation. This can be a dilute sulphuric or hydrochloric acid dip.
Pre-Treatment Matters More Than Usual
Due to the soft and reactive nature of brass it is possible to etch the surface and produce a rough surface that will affect the finish of the coating. Short controlled dip times in the pre-treatment process are recommended for Brass parts, with thorough rinsing between stages.
Specifying the Right Thickness
Typical thicknesses for brass parts are 10 to 25 microns to provide adequate wear resistance and corrosion protection, without excess bulk for precise components.
Corrosion and Wear Benefits
Electroless Nickel Plating creates a hard, uniform surface that offers superior resistance to wear and tarnishing of brass over the bare metal. Data has shown that in humid environments and subject to mild corrosion, electroless nickel coatings out perform other metallic coatings on non-ferrous metals.
Dimensional Considerations for Brass Parts
A coated surface will reproduce all features of the substrate surface. Thus it is essential that prior to coating all surface marks are removed by appropriate machining or polishing. Parts intended for ELN plating of brass components should be inspected before coating.
If you want Electroless Nickel Plating, SWMF is a good place to start.
By specifying the process at the design stage, time is saved and potential problems with parts can be prevented.
