SILICON OXYCARBIDE-BASED ENVIRONMENTAL BARRIER COATING
An article includes a silicon oxycarbide-based layer that has Si, O, and C in a covalently bonded network. The silicon oxycarbide-based layer has first and second opposed surfaces. A calcium-magnesium alumino-silicate-based layer is interfaced with the first surface of the silicon oxycarbide-based layer.
1 . An article comprising:
a silicon oxycarbide-based layer having Si, O, and C in a covalently bonded network, the silicon oxycarbide-based layer having first and second opposed surfaces; and
a calcium-magnesium alumino-silicate-based layer interfaced with the first surface of the silicon oxycarbide-based layer.
2 . The article as recited in claim 1 , wherein the silicon oxycarbide-based layer further includes SiO 2 .
3 . The article as recited in claim 2 , wherein the silicon oxycarbide-based layer includes, by volume, 5-65% of the SiO 2 with a remainder of silicon oxycarbide.
4 . The article as recited in claim 2 , wherein the SiO 2 is a continuous matrix phase with regions of the silicon oxycarbide dispersed there through.
5 . The article as recited in claim 1 , wherein the silicon oxycarbide-based layer further includes a dispersed phase of barium-magnesium alumino-silicate.
6 . The article as recited in claim 5 , wherein the silicon oxycarbide-based layer includes, by volume, 1-30% of the dispersed phase of barium-magnesium alumino-silicate.
7 . The article as recited in claim 1 , wherein the silicon oxycarbide-based layer further includes a continuous matrix phase of SiO 2 and a dispersed phase of barium-magnesium alumino-silicate.
8 . The article as recited in claim 1 , wherein the silicon oxycarbide-based layer further includes a continuous matrix phase of barium-magnesium alumino-silicate and a dispersed phase of SiO 2 .
9 . The article as recited in claim 1 , wherein the silicon oxycarbide-based layer further includes a continuous matrix phase of SiO 2 or barium-magnesium alumino-silicate, the silicon oxycarbide-based layer including, by volume, 5-65% of the continuous matrix phase, and 1-30% of a dispersed phase of the other of the SiO 2 or barium-magnesium alumino-silicate, with a remainder of silicon oxycarbide.
10 . The article as recited in claim 1 , wherein the calcium-magnesium alumino-silicate-based layer partially penetrates into the silicon oxycarbide-based layer such that at least a central core of the silicon oxycarbide-based layer is free of calcium-magnesium alumino-silicate-based material.
11 . The article as recited in claim 1 , wherein the silicon oxycarbide-based layer has a composition SiO x M z C y , where M is at least one metal, x<2, y>0 and z<1 and x and z are non-zero.
12 . The article as recited in claim 1 , wherein the silicon oxycarbide-based layer is thicker than the calcium-magnesium alumino-silicate-based layer.
13 . The article as recited in claim 1 , wherein the calcium-magnesium alumino-silicate-based layer has an average thickness of 1 micrometer to 3 millimeters.
14 . The article as recited in claim 1 , wherein the silicon oxycarbide-based layer includes discrete regions of silicon oxycarbide-based material, the discrete regions having an average maximum dimension of 1-75 micrometers.
15 . The article as recited in claim 1 , the calcium-magnesium alumino-silicate-based layer sealing the silicon oxycarbide-based layer from oxygen diffusion and steam recession into the silicon oxycarbide-based layer.
16 . A composite comprising:
a silicon oxycarbide-based material having Si, O, and C in a covalently bonded network, the silicon oxycarbide-based material having a surface; and
a calcium-magnesium alumino-silicate-based material interfaced with the surface of the silicon oxycarbide-based material.
17 . The composite as recited in claim 16 , wherein the silicon oxycarbide-based material further includes a dispersed phase of barium-magnesium alumino-silicate.
18 . The composite as recited in claim 17 , wherein the silicon oxycarbide-based material includes, by volume, 1-30% of the dispersed phase of barium-magnesium alumino-silicate.
19 . The composite as recited in claim 16 , wherein the silicon oxycarbide-based material further includes a continuous matrix phase of SiO 2 or barium-magnesium alumino-silicate, and a dispersed phase of the other of barium-magnesium alumino-silicate or SiO 2 .
20 . The composite as recited in claim 16 , wherein the silicon oxycarbide-based material has a composition SiO x M z C y , where M is at least one metal, x<2, y>0 and z<1 and x and z are non-zero.