Environmental barrier multi-phase abradable coating
Disclosed is a multi-phase abradable coating including a ceramic matrix and a dislocator phase.
1. A multi-phase abradable coating comprising a ceramic matrix and a dislocator phase dispersed in the ceramic matrix,
wherein the dislocator phase transforms to a micro-cracked phase through exposure to a combustion gas atmosphere,
wherein the multi-phase abradable coating has a porosity of 5 to 10%,
wherein the ceramic matrix comprises hafnium dioxide, a rare earth disilicate, a rare earth monosilicate, BSAS, hafnium silicate, or a combination thereof.
2. The multi-phase abradable coating of claim 1 , wherein the micro-cracked phase is located near the surface of the abradable coating.
3. The multi-phase abradable coating of claim 1 , wherein the multi-phase abradable coating has a thickness of 2 to 50 mils.
4. The multi-phase abradable coating of claim 1 , wherein the dislocator phase is present in an amount of 5 to 25 volume percent.
5. A shroud for a gas turbine engine turbine section comprising a coating system, and a ceramic component, wherein the coating system comprises a multi-phase abradable coating in combination with a top coat, a bond coat, or a combination thereof,
wherein the multi-phase abradable coating comprises a ceramic matrix and a dislocator phase dispersed in the ceramic phase wherein the dislocator phase transforms to a micro-cracked phase through exposure to a combustion gas atmosphere,
wherein the multi-phase abradable coating has a porosity of 5 to 10%,
wherein the ceramic matrix comprises hafnium dioxide, a rare earth disilicate, a rare earth monosilicate, BSAS, hafnium silicate, or a combination thereof.
6. The shroud of claim 5 , wherein the micro-cracked phase is located near the surface of the abradable coating.
7. The shroud of claim 5 , wherein the bond coat is disposed on the ceramic component and the top coat is disposed between the bond coat and the multi-phase abradable coating.
8. The shroud of claim 5 , wherein the coating system comprises a top coat disposed between the ceramic component and the multi-phase abradable coating.
9. The shroud of claim 5 , wherein the coating system comprises a bond coat disposed between the ceramic component and the multi-phase abradable coating.
10. The shroud of claim 5 , wherein the bond coat comprises silicon.
11. The shroud of claim 5 , wherein the top coat comprises hafnium dioxide, a rare earth disilicate, or a combination thereof.
12. The shroud of claim 5 , wherein the top coat and the ceramic matrix comprise the same material.