PROTECTIVE COATING
A barrier layer for an article according to an exemplary embodiment of this disclosure, among other possible things includes a bond coat comprising a matrix, diffusive particles disposed in the matrix, and gettering particles disposed in the matrix. The composition of the gettering particles is a reaction product of the chemical reaction of Equation 1 defined by Equation 2: Si w O x C y N z + ξ O 2 = w Si O 2 + y CO + z 2 N 2 Equation 1 ξ = 2 w + y - x 2 Equation 2 A barrier layer is also disclosed.
1 . A barrier layer for an article, comprising:
a bond coat comprising a matrix, diffusive particles disposed in the matrix, and gettering particles disposed in the matrix, wherein the composition of the gettering particles is a reaction product of the chemical reaction of Equation 1 defined by Equation 2:
Si
w
O
x
C
y
N
z
+
ξ
O
2
=
w
Si
O
2
+
y
CO
+
z
2
N
2
Equation
1
ξ
=
2
w
+
y
-
x
2
Equation
2
2 . The barrier layer of claim 1 , wherein z is zero and at least two of w, x, and y are greater than zero.
3 . The barrier layer of claim 2 , wherein each of w, x, and y are greater than zero.
4 . The barrier layer of claim 1 , wherein x is zero and at least two of w, y, and z are greater than zero.
5 . The barrier layer of claim 4 , wherein each of w, y, and z are greater than zero.
6 . The barrier layer of claim 1 , wherein y is zero and at least two of w, x, and z are greater than zero.
7 . The barrier layer of claim 6 , wherein each of w, x, and z are greater than zero.
8 . The barrier layer of claim 1 , wherein w is greater than zero and at least two of x, y, and z are greater than zero.
9 . The barrier layer of claim 1 , wherein Ω=ξ/(y+z/2) and Ω is greater than or equal to 1.
10 . The barrier layer of claim 9 , wherein the ratio of silicon to carbon (Si:C) is greater than 0.75.
11 . The barrier layer of claim 10 , wherein the ratio of silicon to nitrogen (Si:N) is greater than 0.75.
12 . The barrier layer of claim 11 , wherein the ratio of silicon to oxygen (Si:O) is greater than 1.
13 . The barrier layer of claim 1 , wherein the matrix is substantially pure silicon dioxide.
14 . An article comprising:
a substrate; and
a barrier layer disposed on the substrate, the barrier layer comprising:
a matrix of substantially pure silicon dioxide,
diffusive particles disposed in the matrix, and
gettering particles disposed in the matrix, wherein the composition of the gettering particles is a reaction product of the chemical reaction of Equation 1 defined by Equation 2:
Si
w
O
x
C
y
N
z
+
ξ
O
2
=
w
Si
O
2
+
y
CO
+
z
2
N
2
Equation
1
ξ
=
2
w
+
y
-
x
2
Equation
2
15 . The article of claim 14 , wherein w is greater than zero and at least two of x, y, and z are greater than zero.
16 . The article of claim 14 , wherein Ω=ξ/(y+z/2) and Ω is greater than or equal to 1.
17 . The article of claim 16 , wherein the ratio of silicon to carbon (Si:C) is greater than 0.75.
18 . The article of claim 17 , wherein the ratio of silicon to nitrogen (Si:N) is greater than 0.75.
19 . The article of claim 18 , wherein the ratio of silicon to oxygen (Si:O) is greater than 1.
20 . The article of claim 1 , wherein the substrate is a ceramic matrix composite substrate.