US 11,873,569 B2
Coating for internal surfaces of an airfoil and method of manufacture thereof
Lei Chen, South Windsor, CT (US); Lesia V. Protsailo, Bolton, CT (US); and Michael N. Task, Vernon, CT (US)
Assigned to RTX CORPORATION, Farmington, CT (US)
Filed by RTX CORPORATION, Farmington, CT (US)
Filed on Jul. 13, 2020, as Appl. No. 16/927,417.
Application 16/927,417 is a division of application No. 15/605,720, filed on May 25, 2017, granted, now 10,711,361.
Prior Publication US 2020/0347506 A1, Nov. 5, 2020
Int. Cl. C25D 5/12 (2006.01); F01D 5/18 (2006.01); C25D 7/00 (2006.01); C25D 5/50 (2006.01); C23C 18/50 (2006.01); C23C 18/16 (2006.01); C23C 18/32 (2006.01); B32B 15/04 (2006.01); C22C 27/06 (2006.01); C25D 3/56 (2006.01); F01D 5/28 (2006.01)
CPC C25D 5/12 (2013.01) [B32B 15/04 (2013.01); C22C 27/06 (2013.01); C23C 18/165 (2013.01); C23C 18/1616 (2013.01); C23C 18/1692 (2013.01); C23C 18/32 (2013.01); C23C 18/50 (2013.01); C25D 3/56 (2013.01); C25D 5/50 (2013.01); C25D 7/008 (2013.01); F01D 5/187 (2013.01); B32B 2603/00 (2013.01); F01D 5/288 (2013.01); F05D 2230/90 (2013.01); F05D 2300/121 (2013.01); F05D 2300/132 (2013.01); F05D 2300/21 (2013.01); F05D 2300/2112 (2013.01); F05D 2300/611 (2013.01); F05D 2300/701 (2013.01)] 15 Claims
OG exemplary drawing
 
1. An airfoil comprising:
an internal surface having disposed thereon:
a thermally grown oxide layer that comprises alumina and chromium oxide; and
a layer comprising Ni—Cr/aluminide or Cr/aluminide disposed between the layer comprising alumina and chromium oxide and the internal surface of the airfoil; where the layer comprising Ni—Cr/aluminide or Cr/aluminide contains aluminum and chromium that vary in amount inversely with one another with distance from the internal surface of the airfoil or from a surface of the thermally grown oxide layer.