Thermal barrier coatings
AssigneeThe Penn State Research Foundation
InventorsDouglas E. Wolfe, Michael P. Schmitt
Life of this patent
Estimating the term…
Abstract
High temperature stable thermal barrier coatings useful for substrates that form component parts of engines such as a component from a gas turbine engine exposed to high temperatures are provided. The thermal barrier coatings include a multiphase composite and/or a multilayer coating comprised of two or more phases with at least one phase providing a low thermal conductivity and at least one phase providing mechanical and erosion durability. Such low thermal conductivity phase can include a rare earth zirconate and such mechanical durability phase can include a rare earth a rare earth aluminate. The different phases are thermochemically compatible even at high temperatures above about 1200° C.
Claims20
A thermal barrier coating over a substrate, the thermal barrier coating comprising a multiphase composite layer comprised of two or more phases with at least one phase providing a low thermal conductivity and at least one phase providing durability,
- wherein the low thermal conductivity phase comprises a rare earth zirconate having about 5 to about 80 mol % RE2O3, where RE is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sc,
- wherein in the multiphase composite layer the low thermal conductivity phase includes a pyrochlore phase (RE2Zr2O7), and/or a delta phase (RE4Zr4O12),
- the durability phase in the multiphase composite layer comprises a rare earth aluminate and has a weight fraction greater than 51 wt. % and not exceeding 95 wt. %,
- the aluminate consists of a perovskite phase including YAP, LAP, CAP, PAP, PmAP, SAP, EAP, GAP, TAP, DAP, HAP, ErAP, TmAP, YbAP, LuAP, ScAP, and
- the rare earth aluminate is thermodynamically stable in contact with the low thermal conductivity phase at temperatures of at least 1200° C.
A thermal barrier coating over a substrate, the thermal barrier coating comprising a multiphase composite and/or a multilayer coating consisting of two phases with one phase providing a low thermal conductivity and the other phase providing durability,
- wherein the low thermal conductivity phase consists of a rare earth zirconate having about 5 to about 80 mol % RE2O3, where RE is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sc,
- the durability phase consists of a rare earth aluminate and has a weight fraction between 0.5 wt. % and 95 wt. %,
- the aluminate consists of a perovskite phase (RE2O3), where the rare earth is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and
- the rare earth aluminate is thermodynamically stable in contact with the low thermal conductivity phase at temperatures of at least 1200° C.,
- wherein the thermal barrier coating comprises a plurality of alternating layers of the low thermal conductivity phase and the durability phase.
A thermal barrier coating over a substrate, the thermal barrier coating comprising a multilayer coating comprised of two or more phases with at least one phase providing a low thermal conductivity and at least one phase providing durability,
- wherein the low thermal conductivity phase comprises a rare earth zirconate having about 5 to about 80 mol % RE2O3, where RE is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sc,
- the durability phase comprises a rare earth aluminate and has a weight fraction between 0.5 wt. % and 95 wt. %,
- the aluminate consists of a perovskite phase, where the rare earth is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and
- the rare earth aluminate is thermodynamically stable in contact with the low thermal conductivity phase at temperatures of at least 1200° C.,
- the thermal barrier coating comprising a plurality of alternating layers of the low thermal conductivity phase and the durability phase.
A thermal barrier coating over a substrate, the thermal barrier coating comprising a multiphase composite layer comprised of two or more phases with at least one phase providing a low thermal conductivity and at least one phase providing durability,
- wherein the low thermal conductivity phase comprises a rare earth zirconate having about 5 to about 80 mol % RE2O3, where RE is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sc,
- wherein in the multiphase composite layer the low thermal conductivity phase includes a pyrochlore phase (RE2Zr2O7), and/or a delta phase (RE4Zr4O12),
- the durability phase in the multiphase composite layer comprises a rare earth aluminate and has a weight fraction greater than 51 wt. % and not exceeding 95 wt. %,
- the aluminate is in the perovskite phase including YAP, LAP, CAP, PAP, PmAP, SAP, EAP, GAP, TAP, DAP, HAP, ErAP, TmAP, YbAP, LuAP, ScAP, or garnet phase, or monoclinic phase, where the rare earth of the garnet phase or monoclinic phase is selected from Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, and
- the rare earth aluminate is thermodynamically stable in contact with the low thermal conductivity phase at temperatures of at least 1200° C.,
- wherein the rare earth aluminate and the rare earth zirconate have the same rare earth element.
Dependencies are inferred from the claim text.