The “Magical” Process: Fluoride Ion Cleaning

Do you ever wonder how we restore and maintain hot section engine components? After all, these crucial parts undergo a lot of wear and tear—but whether you operate commercial or military aircraft, it’s vital to extend the life of these components and ensure their ongoing safety and operation.

Walbar Peabody is a trusted repair station when it comes to the General Electric CF6 engine series, the longest-running in commercial aviation. More specifically, we repair low-pressure turbine nozzles for this engine series.

Hot section engine components are routinely damaged due to oxidation, hot corrosion, fatigue, and more. That’s where we step in. It’s our job to properly overhaul these parts, which requires numerous operations strategically designed to yield successful overhauls. 

One such process is that of Fluoride Ion Cleaning. Keep reading to learn what this intriguing procedure entails.

What is Fluoride Ion Cleaning (FIC)?

In order to effectively repair (ultimately fill) cracks, they must be “clean.” Due to the nature and composition of the superalloy that engine components are made of, an oxide scale builds up in these cracks, which is very difficult to remove. 

FIC is a complex process that is highly effective for removing deeply embedded oxides within parts. It’s crucial, particularly before braze repairing the component (i.e., joining the parts using a filler metal). This is because the filler won’t stick to oxides, which could lead to weak joints. 

The complex chemical reaction between hydrogen fluoride, aluminum, and titanium essentially pulls the oxide scale out to the surface of the turbine nozzles, using a carefully designed cycle with specific:

• Times
• Temperatures
• Pressures
• Parameters

Simply put, the component is rid of contaminants, even in the narrowest of micro-cracks, that can negatively affect the filling of cracks in the part. FIC ensures more effective braze repairs.