| 摘要 |
Turbine shroud abradable coatings that balance the apparently contradictory requirements of high flowpath solidity, low blade tip wear, and good durability in service. The shrouds include a shroud substrate (12), a coating system (20), and an abradable coating (14). The coating system overlies at least a portion of an outer surface of the shroud substrate. The coating system includes a bond coat, a thermal barrier coating (TBC), and/or an environmental barrier coating (EBC). The abradable coating overlies at least a portion of the barrier coating. The abradable coating defines a substantially smooth continuous flowpath surface. The abradable coating includes a hybrid microstructure including a relatively dense, high-durability phase corralling relatively porous abradable phases. The second phases are relatively more abradable by the blades of a turbine than the second regions. |
