Silicon oxycarbide environmental barrier coating
An article includes a ceramic-based substrate and a barrier layer on the ceramic-based substrate. The barrier layer includes a matrix of barium-magnesium alumino-silicate or SiO 2 , a dispersion of silicon oxycarbide particles in the matrix, and a dispersion of particles, of the other of barium-magnesium alumino-silicate or SiO 2 , in the matrix.
1. A composite material comprising:
a matrix of barium-magnesium alumino-silicate or SiO 2 ;
a dispersion of silicon oxycarbide particles in the matrix, the silicon oxycarbide particles having Si, O, and C in a covalently bonded network; and
a dispersion of particles, of the other of barium-magnesium alumino-silicate or SiO 2 , in the matrix, wherein the composite material forms a layer having a first side and a second side, and wherein barium-magnesium alumino-silicate particles are concentrated near the first side, thereby forming a sealing layer.
2. The composite material as recited in claim 1 , including, by volume, 1-30% of the barium-magnesium alumino-silicate particles, 5-40% of the matrix of SiO 2 , and a balance of the silicon oxycarbide particles.
3. The composite material as recited in claim 2 , including, by volume, 1-5% of the barium-magnesium alumino-silicate particles.
4. The composite material as recited in claim 1 , wherein the matrix of SiO 2 is continuous.
5. The composite material as recited in claim 1 , including, by volume, 30-94% of the silicon oxycarbide particles, 5-40% of the matrix of SiO 2 , and 1-5% of the barium-magnesium alumino-silicate particles.
6. The material of claim 1 , wherein the silicon oxycarbide particles have a composition SiO x M z C y , where M is at least one metal, x<2, y>0, z<1, and x and z are non-zero.
7. The material of claim 1 , wherein the second side of the layer is adjacent a substrate.
8. The material of claim 1 , wherein a cationic metal species from the barium-magnesium alumino-silicate particles is diffused into the silicon oxycarbide particles.
9. The material of claim 1 , wherein an average maximum dimension of the silicon oxycarbide particles is between 1 and 75 micrometers.
10. The material of claim 9 , wherein an average maximum dimension of the silicon oxycarbide particles is between 44 and 75 micrometers.
11. A composite material comprising:
a matrix of barium-magnesium alumino-silicate or SiO 2 ;
a dispersion of silicon oxycarbide particles in the matrix, the silicon oxycarbide particles having Si, O, and C in a covalently bonded network; and
a dispersion of particles, of the other of barium-magnesium alumino-silicate or SiO 2 , in the matrix, wherein the composite material includes, by volume, 30-94% of the silicon oxycarbide particles, 5-40% of the matrix of SiO 2 , and 1-5% of the barium-magnesium alumino-silicate particles.