US 12,304,874 B2
Method for fabricating an environmental barrier coating on a ceramic matrix composite
Imelda P. Smyth, North Palm Beach, FL (US); and Sarah A. Frith, Jupiter, FL (US)
Assigned to RTX CORPORATION, Farmington, CT (US)
Filed by RTX CORPORATION, Farmington, CT (US)
Filed on Sep. 21, 2023, as Appl. No. 18/471,373.
Application 18/471,373 is a division of application No. 16/536,629, filed on Aug. 9, 2019, granted, now 11,866,380.
Prior Publication US 2024/0010574 A1, Jan. 11, 2024
Int. Cl. C04B 41/50 (2006.01); C04B 35/565 (2006.01); C04B 41/45 (2006.01)
CPC C04B 41/5066 (2013.01) [C04B 35/565 (2013.01); C04B 41/4527 (2013.01); C04B 41/4543 (2013.01); C04B 41/5024 (2013.01); C04B 41/5042 (2013.01); C04B 41/5059 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method of fabricating a coating, the method comprising:
providing a ceramic matrix composite that includes SiC fibers disposed in a SiC matrix;
depositing a base slurry on the ceramic matrix composite, wherein the base slurry contains, in parts by weight, 35-60 of a metal oxide powder, 5-20 of at least one of silicon carbide powder, silicon nitride powder, or free silicon powder, and 0.2-10 of barium-magnesium-aluminosilicate powder in a first carrier fluid;
drying the deposited base slurry to produce a base green layer;
depositing a transition slurry on the base green layer, wherein
the transition slurry contains, in parts by weight, 35-60 of a metal oxide powder, an amount X1 of at least one of silicon carbide powder, silicon nitride powder, or free silicon powder, an amount X2 of at least one of zirconium carbide powder, zirconium nitride powder, or zirconium oxide powder, and 0.2-10 of barium-magnesium-aluminosilicate powder in a second carrier fluid,
the total amount of X1+X2 is 5-20, and
the amount X1 is decreased and the amount of X2 is increased through the deposition of the transition slurry;
drying the deposited transition slurry to produce a transition green layer; and
forming a consolidated coating on the ceramic matrix composite by heating the base green layer and the transition green layer.