By means of modern preparation and plating techniques we can obtain very smooth (intermediate) ductile nickel coatings with the capability of sealing steel completely and of obtaining thick coatings for repair purposes. Steel is non-homogeneous and mostly contains micro-defects. This is not the most suitable
substrate for hard corrosion resistant mono layer coatings (such as hardened Lunac, HVOF ceramics or hard chromium) to protect steel from corrosion. Unlike almost any other coating, Lunac coatings give a guaranteed full bond with this technical nickel substrate resulting in completely micro-crack free structure !
|The application of technical hard nickel is one of the very few
galvanic processes with good micro-scale repair capability.
Features and applications:
- The multi layer technical hard nickel / Lunac system offers ultimate corrosion protection to parts in (tropical) harsh environments such as marine or even submarine environments !
Because the ductility of this coating is outstanding it offers an additional corrosion protection to parts that may be slightly damaged (indented) during service (last pictures), without losing its corrosion protection capability. (The hard top layer may possibly crack, but the intermediate nickel layer can elongate up to 30%).
The WMV pre-treatment process offers the same unparalleled high degree of coating bond with the substrates as is the case with our Lunac coatings. This property allows the deposition of very thick repair layers (> 500 µm / 0.02").
Above: this damaged plastic processing extrusion part was locally repaired by technical nickel plating, followed by precision grinding (-0.0125 to -0.025 mm (- 1/2 to 1 mil). Additionall, the melt flow canals were Lunac 1 plated to acquire improved non-stick effects and corrosion protection as well.
Right: calibration tube was conically worn by 700 µm / 0.028". With our repair nickel plating process the tube was effectively renovated. Additionally 55 µm / 0.0021" Lunac 2+ was applied on top of this nickel to reduce the wear rate by a factor of 80. In both cases the full substrate bond is a requisite.
The high ductility of the intermediate nickel coating and full bond strength between the various layers is vital for applications in harsh environments. Offshore equipment (such as on-board hydraulics or dredging machinery) is highly subject to corrosion as well as a high risk of indentation. A slightly damaged part maintains its functionality by means of the ductile nickel sub layer that will still protect the part from corrosion.