Other technologies

Liquid ionic Nitrocarburizing

HEF Group is the worldwide leader in the domain of nictrocarburizing in ionic liquid environment. For more than 50 years, it operates thermochemical CLIN treatments (Controlled Liquid Ionic Nitrocarburizing) mainly on ferrous alloys (steel, cast iron, stainless steel,…). These salt bath treatments improve the hardness gradient and the compression constraint gradient to increase the wear resistance and the fatigue of the material.

The CLIN treatments can be accompanied with a passivation step offering an excellent resistance to corrosion. Certain parts can then last for more than 700 hours in saline mist thanks to such a treatments.

Thermal projection

HEF Group disposes of various thermal projection technologies used to coat a large range if materials.

The arc or flame projection permits the improvement for wear or corrosion resistance, to make conductive or insulating thermic/electric, and to improve the friction of all types of inorganic materials expect copper.

The plasma projection is destined to inorganic materials at the exception of copper to confer them numerous properties:

  •  Refractory coatings
  •  Abrasion and erosion resistance
  •  Fretting corrosion resistance
  •  Wear resistance
  •  Corrosion resistance
  •  Improvement of friction properties in hostile environment

Powder coating (LIFCO)

Subsidiary of HEF Group since 2011, the company LIFCO industry elaborates mutli-material or composite powders, in particular used for the thermal and electrostatic projection surface coating thanks to the projection technology in fluidized bed.

Surface preparation & finishing

An important part of the success of a mechanical vacuum deposition lies in the surface condition of the initial part, especially its roughness.
A high roughness leads:
- To  a bad friction in lubricated environment
- to the wear of the counter surface of the coated part
Among the processes used, the tribofinishing process has many advantages:
- Keeps geometry of the part (does not generate ripples)
- Parts relatively clean after polishing
On the other hand, polishing a large number of parts can generate several problems:
- Possibilities of interaction between the parts (collisions, scratches ...) which limits the density of the part to polish in bulk.
- Complicated unloading of parts in a bowl of large volume and risk of corrosion during this time.
However, bulk polishing remains inescapable for some parts, either because their small quantity does not justify the use of an assembly, or because their geometry is not suitable.