CoNiCrAlY is a Cobalt-Nickel-Chromium-Aluminum-Yttrium coating. It serves as a bond coat or overlay on superalloy components, often in turbine and aerospace applications. The coating is built to resist heat and oxidation, which is exactly what makes it difficult to remove.
Removing it requires stripping the tough metallic layer without corroding or warping the superalloy substrate underneath. Get the process wrong and the part is scrap. Get it right and the part is ready for recoating and return to service.
This post explains the three primary methods for removing CoNiCrAlY, how each one works, and when to use it. KayTech Inc provides thermal barrier coating removal services, including CoNiCrAlY and CoCrAlY removal.
What is CoNiCrAlY and why is it hard to remove?
CoNiCrAlY is a metallic overlay coating applied to superalloy parts. It’s purpose is to provide corrosion resistance to the substrate and act as a bond coat prior to the application of a thermal barrier coating or TBC. These coatings are designed to be exposed to extremely high temperature gases under tremendous pressure.
That durability is the problem during removal. The coating resists the same chemical and thermal stresses that a removal process relies on. The substrate beneath it is also a high-value superalloy, so any method that attacks the coating must spare the base metal.
Removal of CoNiCrAlY
Three factors drive the choice of removal method: the substrate material, the coating thickness, and the part geometry. A thin coating on a flat surface calls for a different approach than a thick coating inside a complex internal passage.
Protect the substrate, protect the part
CoNiCrAlY removal succeeds when the coating comes off clean and the substrate stays sound. The wrong method, or the right method run with the wrong parameters, corrodes or warps a high-value part. The correct method, controlled properly, returns the part ready for recoating.
KayTech Inc removes a variety of thermal barrier coatings for industrial gas turbines, aero-derivative turbines and aerospace industries. Contact KayTech to discuss your part, your substrate, and your removal requirements.
Where is Kaytech located?
Kaytech Inc. operates in the Upstate of South Carolina and serves multiple markets including Arizona, Connecticut, Massachusetts and of course South Carolina and North Carolina.
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