摘要 |
A method of protecting a component, in particular a turbine blade, from the effects of hot corrosion includes the steps of applying a chromium diffusion coating to the component and applying a coating of a ceramic material to one or more selected regions of the chromium diffusion coating. The selected regions are regions which, in subsequent use of the component, are subjected to temperatures lower than a predetermined temperature. The ceramic material preferably includes a binder combined with a metal oxide. In a preferred embodiment, a turbine blade is coated over the whole of its internal and external surfaces with the chromium diffusion coating; an aluminum diffusion coating is then applied, through a mask, to the aerofoil surfaces and the internal surfaces of the blade; the mask is removed and the ceramic material is applied as an overlay to the chromium diffusion coating in a region between the platform and the root of the blade. |