Patent ID: 11873569
Assignee: RTX CORPORATION
Field: Surface technology, coating (Chemistry)
Classification: CPC C  B  F | IPC B  C  F

Claim 5:
6. The airfoil of claim 1, prepared by a method comprising:
providing the airfoil to be coated; wherein the internal surface comprises a convoluted internal passage;
electrolytically applying a first layer that comprises chromium or a chromium alloy onto the inner surface;
electrolytically applying a second layer comprising aluminum or an aluminum alloy onto the first layer; and
heat treating the airfoil to promote interdiffusion between the first layer and the second layer to form the thermally grown oxide layer that comprises alumina and chromium oxide; and the layer comprising Ni—Cr/aluminide or Cr/aluminide disposed between the layer comprising alumina and chromium oxide and the internal surface of the airfoil.