WMV

Both hard and corrosion resistant Lunac 1 and 2+ industrial coatings can stay fully crack free in case the substrate is free of serious defects and ground smothly !! Good corrosion resistance can not only be obtained by higher electro potentials but also by means of stress free lattices or even better, crystal lattice free amorphous structures. In this way a material or coating with lower electro potentials but crystal free structure can deliver the same corrosion resistance as a more noble crystalline material. The advantages are less risky electro potential differences and cost savings. There are Lunac versions with no crystal structure and hardly any potential difference to steel. A hard coating such as Lunac that contains crack inhibiting compressive stresses is very rare.

Corrosion testing:

Duplo Lunac coatings are able to seal almost all steel surfaces completely and
comply with the NSS B117 salt spray testing by full rating 10 (no single rust spot).

In the diagrams below you can find the corrosion levels for the Lunac 1
and Lunac 2hc+ version, compared to some other materials.
















This corrosion testing diagram displays two different metals types in corrosion perspective:

1. Metals with improved resistance to oxidizing environment such as HNO3 or H2O2. These metals can benefit from the metal oxide developing action of these chemicals provided the metal oxide layer is dense and offers good bonding. Chromium, Titanium, Stainless steel or Aluminum are good examples of these metals or alloys. Lunac coatings, copper or steel do not follow with this mechanism and are less chemical resistant in these environments.
2. Metals with improved resistance to non-oxidizing acidic environments such as HCl, H2SO4, HF, acetic acid, citric acid etc. Therefore, the majority of acids. These metals and alloys mostly benefit from a higher electro potential, so the half noble and noble metals. Copper, Tin, Nickel, Lunac 1 and 2+ or silver are good examples of these metals or alloys. The metals as mentioned at 1. are visa versa not well resistant to these acids.
   
   
   
   
   
   
   Figure 1: The consequences of porosity in flame sprayed ceramic coating on 1.4462 with high pitting resistance became visible after the ceramic coating was turned off from this ship axle. The under corrosion reached out over +/- 4 mm depth and did hardly swell. Most likely the steel suffered from this corrosion because of a devastating salt concentration effect, despite the application of the highly see water resistant Chromium-Nickel steel. Lunac coatings proved to inhibit this effect due to the dense structure, good heat conductance and their inertness. Below: WMV salt spray tester.
   

Figure 2: Lunac 1 (displayed left) and Lunac 2+ coatings contain compressive stresses and will consequently inhibit micro cracks formation during hardening. Hard chromium coatings (displayed below) tend to develop micro cracks after being deposited, due to tensile stresses. These micro cracks often compromise the general corrosion resistance.