| abstract |
A coating for protecting the surfaces of gas turbine components such as single crystal turbine blades and vanes, wherein the coating has a composition (in weight percent) consisting essentially of chromium, 15-35; aluminium 8-20; tantalum, 1-10; tantalum plus niobium, 0-10; silicon, 0.1-1.5; hafnium, 0.1-1.5; yttrium, 0-1; cobalt, 0-10; and nickel, balance totalling 100 percent. A preferred coating, which is particularly desirable for use with single-crystal turbine blades and vanes, has a composition consisting essentially of chromium, 17-23; aluminium, 10-13; tantalum plus niobium, 3-8; silicon, 0.1-1.5; hafnium, 0.1-1.5; yttrium, 0-0.8; cobalt, 0-trace; and nickel, balance totalling 100 percent. A process for preparing the coated component comprises applying a coating of the above composition to a substrate. |