Optimizing Cu‐Cr Coatings for Environmental Protection of Copper Alloys
Cu-Cr barrier coatings, with suitably matched thermal and physical properties, are being developed to protect Cu-alloy liners of rocket engine thrusters via the formation of Cr 2 O 3 barriers. The challenge is to maximize Cr 2 O 3 protection with minimal Cr addition, since high Cr content degrades the coating conductivity and ductility. It is shown that, by using an efficient coating technique to produce a refined coating microstructure, adequate protection is achieved even while Cr content is reduced by nearly half from the current state-of-the-art levels.