Corrosion prevention in copper combustion chamber liners of liquid oxygen/methane booster engines

The use of a protective gold coating for preventing the corrosion of copper combustion chamber liners in liquid oxygen/methane booster engines is discussed with reference to experimental results. Gold-plated and unplated copper alloy specimens were tested in a carbothermal test facility providing realistic simulations of booster engine cooling channel conditions, such as temperature, pressure, flow velocity, and heat flux. Metallographic examinations of the unplated specimens showed severe corrosion as a result of the reaction with the sulfur-containing contaminant in the fuel. In contrast, gold-plated specimens showed no corrosion under similar operating conditions.