Turbine blade tip and shroud clearance control coating system
AssigneeHoneywell International Inc.
InventorsThomas E. Strangman, Derek Raybould, Paul Chipko, Malak F. Malak
Life of this patent
Estimating the term…
Abstract
A turbine blade tip and shroud clearance control coating system comprising an abrasive blade tip coating and an abradable shroud coating are provided. The abrasive layer may comprise abrasive particles of cubic zirconia, cubic hafnia or mixtures thereof, and the abradable layer may be a nanolaminate thermal barrier coating that is softer than the abrasive layer. The invention further provides an alternate coating system comprising an abradable blade tip coating and an abrasive shroud coating.
Claims20
A turbine blade tip and shroud clearance control coating system comprising:
- a turbine blade, the turbine blade comprising a blade tip;
- an abrasive grit coating disposed on the blade tip, the abrasive grit coating comprising an oxidation resistant bond coating and grit particles embedded into the oxidation resistant bond coating and grit particles embedded into the oxidation resistant bond coating, wherein the grit particles comprise abrasive crystalline particles of cubic zirconia, cubic hafnia or mixtures thereof;
- a turbine shroud, the shroud comprising an inner surface, wherein the inner surface is in a rub relationship with the blade tip;
- and
- a nanolaminate thermal barrier coating on the inner surface of the turbine shroud, the nanolaminate thermal barrier coating comprising alternating layers of a first material with a second material, the first material comprising stabilized zirconia, hafnia or mixtures thereof, and the second material comprising at least one metal oxide, wherein the nanolaminate thermal barrier coating comprises from about 5 wt % to about 70 wt % of the metal oxide and from about 30 wt % to about 95 wt % of stabilized zirconia, hafnia or mixtures thereof.
A turbine blade tip and shroud clearance control coating system comprising:
- a silicon nitride turbine blade, the turbine blade comprising a blade tip;
- an abrasive grit coating disposed on the blade tip, the abrasive grit coating comprising:
- an oxidation resistant bond coating, the oxidation resistant bond coating comprising a refractory metal silicide braze;
- grit particles embedded into the oxidation resistant bond coating, wherein the grit particles comprise abrasive crystalline particles of cubic zirconia, cubic hafnia or mixtures thereof;
- a turbine shroud, the shroud comprising an inner surface, wherein the inner surface is in a rub relationship with the blade tip;
- and
- a nanolaminate thermal barrier coating on the inner surface of the turbine shroud, the nanolaminate thermal barrier coating comprising alternating nanolayers of a first material with a second material, the first material comprising stabilized zirconia, hafnia or mixtures thereof, and the second material comprising at least one metal oxide, wherein the alternating nanolayers have varying thicknesses.
A turbine blade tip system comprising:
- a turbine blade, the turbine blade comprising a blade tip;
- and
- an abrasive grit coating disposed on the blade tip, the abrasive grit coating comprising an oxidation resistant bond coating and grit particles embedded into the oxidation resistant bond coating, wherein the grit particles comprise abrasive crystalline particles of cubic hafnia.
Dependencies are inferred from the claim text.