Patent ID: 7115171
Filing Date: 2006-10-03
Classification: C11D,C23G

Abstract:
1. A method comprising the following steps: (a) providing a turbine component having a surface with engine deposits formed thereon during operation of a gas turbine engine, wherein the turbine component comprises a nickel and/or cobalt-containing base metal; and (b) treating the surface of the turbine component with a cleaning composition to convert the engine deposits thereon to a removable smut without substantially etching the base metal of the turbine component, wherein the cleaning composition comprises an aqueous solution that is substantially free of acetic acid and comprises: a nitrate ion source in an amount, by weight of the nitrate ion, of from about 470 to about 710 grams/liter; and a bifluoride ion source in an amount, by weight of the bifluoride ion, of from about 0.5 to about 15 grams/liter.