Under the heading “wet processes”, CITRA intends to gather the broad family of electrolytic and chemical processes by applying conductive liquids. Indeed, it is necessary to distinguish: the “metallic deposits” which may require an electrolysis current to create one or severals layers of the substrate, and the chemical or electrolytic “conversions”, where the metallurgy of the substrat has a direct influence on the composition of the layer.

Custom development

Each of these modes can be easily done and adapted on demand on the 25 tanks to the CITRA’s pilot plant, on a scale of between 70 and 250L.

Thanks to this flexibility, each development request can be considered, either in term of adapted formulations or implementation of commercial solutions to be tested on test samples and prototypes.

Metal Deposits

This technique is used to obtain metal coatings (Ni, Zn, Cu, Co, Cr …), but also alloys (NiP, NiW, Zn-Ni, Cu-Sn-Zn …) and even ceramic-loaded metal composites (Ni-SiC …). The thicknesses of these coatings are generally between 2 and 100 μm, on often complex geometries. Covering large industrial areas, the applications are very varied and often tailored (improvment of the hardness, corrosion resistance …).

CITRA offers a wide range of coatings and treatments (non-exhaustive list):

  • Copper plating on all materials
  • Micro / nanometric composite Nickel base or Copper base
  • Adapted formulations (NiW, precious metals)
  • Surface activation and preparation
  • Decoating


Conversion treatments

Specific to light alloys (Al, Ti, Mg), anodizing is the common denomination of electrolytic conversions. In order to provide electrical insulation properties, friction, bacterial resistance or improve the adherence of paintings and varnishes, these methods use additives in their chemistry to develop new fonctions.

CITRA offers a wide range of coatings and treatments (non-exhaustive list):

  • Colorful hard anodizing
  • Thick colorful anodizing
  • Titanium anodizing
  • Anodizing formulation (OAS, TSA, OAD, OAC …)
Processes Deposit Conversion
Température range (°C) 20 à 90 -5 à 40
Current density (A/dm²) 0,1 à 30 0,1 à 3
Thickness (µm) 1 à 200 0,1 à 120
Coating’s homogeneity +/- 20% +/- 5%
Deposition speed (µm/h) 10 à 100  15 à 50

Metal Deposits

The most known chemical deposit remains chemical nickel(NiP). Providing good anticorrosive properties (500h BS) and a high hardness (900Hv), it allows a regular thickness, with a deposition speed of the order of 20μm / h.

 

CITRA offers a wide range of coatings and treatments (non-exhaustive list):

  • Nickel and chemical copper
  • Wood Nickel


Chemical conversion treatments

Generally applied for pre-painting preparations, chemical conversions of the type of chromation or phosphatation make it possible to superficially oxidize the surfaces, in the form of complex combination layers, but of limited thickness.

CITRA offers a wide range of coatings and treatments (non-exhaustive list):

  • Chromate
  • Phosphating
  • Zincate without cyanide
Processes Deposit (NiP) Conversion
Température range (°C) 88 Ambient
Current density (A/dm²)
Thickness (µm) 1 to 20 0,1 to 2
Coating’s homogeneity +/- 5% +/- 5%
Deposition’s speed (µm/h) 10 to 25 less than 1µm/min