The embodiments described herein relate to turbine disk assemblies, and in particular, turbine disk assemblies (or blisks) that include ceramic matrix composite (CMC) blades.
Known turbine engines include an air intake portion, a compressor portion, a combustion portion, a turbine portion, and an exhaust portion. Such known turbine engines produce thrust and/or extract energy from a fluid flow by first compressing the intake air within the compressor portion. The compressor portion often includes a series of bladed disks to form a multi-stage, axial compressor. Fuel is added to the compressed air, and the mixture is combusted in the combustion portion. The resulting hot, high pressure gas is then expanded through the turbine portion to extract energy therefrom. The turbine portion often includes a series of bladed disk assemblies to form a multi-stage turbine.
Many known turbine disk assemblies include a series of turbine blades arranged circumferentially about a rotor or disk. Many known blades are constructed from a nickel alloy, and are secured to the rotor by the root of the blade. Some turbine blades include integral platforms extending circumferentially from both the high and low pressure sides of the airfoil near the root of the blade. The platforms can function as flow guides to direct the airflow along a desired flow path. In an effort to improve turbine performance, alternative materials have been used in the construction of some known turbine blades. For example, some known turbine blades are constructed from ceramic matrix composite (CMC) materials, which are lighter and can withstand higher temperatures than conventional nickel alloy blades.
Many known CMC blades, however, do not include an integral flow path platform. Thus, the disk assembly may include additional, non-integral flow paths, which can complicate the attachment and/or compromise the effectiveness of the assembly. Moreover, attachment of known CMC blades to the underlying rotor can be difficult, for example, due to the dissimilarity in the materials.
Thus, a need exists for an improved turbine blisks with CMC blades, and methods for manufacturing the same.