Electroless plating properties
Coatable Alloys and Adhesion
The NIPLATEĀ® range of treatments can be applied to many of the alloys commonly used in mechanical engineering. The adhesion of NIPLATEĀ® coatings is excellent on most of these metal alloys, thanks to the chemical bond that forms between the coating and the base material.
In fact, the nickel plating process includes a specific surface activation step before deposition of the NIPLATEĀ® coating. This step is essential to clean and prepare the surface, making it ready for nickel plating.
For some types of alloys, such as stainless steels or steels that have undergone thermochemical treatments, a preliminary mechanical micro-sandblasting treatment is necessary. This treatment ensures excellent adhesion of the coating to the base metal but increases surface roughness to values ranging between 1.00 and 1.60 Ra.
For the aforementioned steels, a subsequent heat treatment at 280Ā°C or higher is also recommended in order to further improve adhesion. This additional step optimizes the coating adhesion, making the treatment even more effective and durable.
Alloys and Mechanical Pre-treatments
| Alloy | Mechanical pre-treatment |
|---|---|
| Carbon steel | No mechanical pre-treatment required |
| Case-hardened steel | Sandblasting required |
| Stainless steel | Sandblasting required |
| Aluminum alloys | No mechanical pre-treatment required |
| Copper alloys | No mechanical pre-treatment required |
| Titanium alloys | Sandblasting required |
PRACTICAL RECOMMENDATIONS
- Clearly identify the material to be coated in the drawing.
- The material must have no residual magnetism, which can create defects of excessive roughness of the coating on edges and corners.
- The material must be clean or lightly greased with a protective oil that is soluble in water-based detergents.
- The material must not have any surface residues that cannot be removed by the water-based alkaline degreasing pre-treatments (such as oil, grease, cleaning paste, marker marks, adhesive tape residues, etc.)
- The surface must be free of defects (such as cracks, porosity, burrs, heavy oxidation, inclusions, welding slags, uneven alloy composition, etc.) that might create unacceptable coating alterations.