Fluoride Ion Cleaning

Fluoride ion cleaning is a controlled gaseous chemical process that removes:

• Oxide scales
• Corrosion products
• Sulfidation damage
• Thermal barrier coating (TBC) residues
• Embedded contaminants

During fluoride ion cleaning, the component is exposed to fluorine‑containing process gases at high temperatures in a controlled furnace environment to precisely remove oxides and effectively clean the surface.

Superalloy turbine blades can be coated by doped aluminization (CVA) or cleaned during maintenance operations (aluminization removal) using FIC process (Fluoride Ion Cleaning). The FIC process is the best cleaning process to remove oxides on superalloys before welding or brazing operations.

Safe Turbine Blade Cleaning

Turbine blades operate under extreme conditions, including very high temperatures ranging from 800 to 1,500°C, as well as oxidizing and hot corrosion environments caused by salt and sulfur attack. Over time, this exposure leads to the formation of surface oxides, internal oxidation, corrosion layers, and sulfidation damage.

FIC allows removal of these degradation layers without mechanically damaging the base metal, which is critical for expensive superalloy blades.

Precise and Nondestructive

The blade is heated in a furnace (typically 1,000°C) and exposed to a fluoride-containing gas (e.g., HF). Fluoride ions react with metal oxides according to the following reaction:
Metal Oxide + Fluoride → Volatile Metal Fluoride

These metal fluorides either

• Vaporize and leave the surface
• Or form removable compounds

Process advantages:

• Non-mechanical (no grit blasting damage)
• Penetrates small cooling holes in blades
• Preserves dimensional accuracy
• Removes internal oxidation
• Ideal for complex airfoil geometries