Turbine wheel assembly with ceramic matrix composite components

1. A turbine wheel assembly, the assembly comprising

a disc made of metallic materials arranged around a central axis, the disc shaped to define a plurality of slots spaced around a circumference of the disc that each extend radially-inward from a radially-outermost surface of the disc,

a slot-mounted turbine blade including an airfoil made of ceramic matrix composite materials and a root provided by a pair of clamp blocks that engage a radially-inner portion of the airfoil, the root being received in one of the plurality of slots defined by the disc and shaped to block radially-outward movement to decouple the slot-mounted turbine blade from the disc, and

an edge-mounted turbine blade including an airfoil made of ceramic matrix materials and a root provided by a pair of clamp blocks that engage a radially-inner portion of the airfoil, the root being bonded to the radially-outermost surface of the disc to couple the edge-mounted turbine blade to the disc,

wherein the pair of clamp blocks that provide the root of the slot-mounted turbine blade are shaped to provide a first platform that extends circumferentially from the airfoil included in the slot-mounted turbine blade and is spaced radially outward from the radially-outermost surface of the disc to block hot gases interacting with a radially-outer portion of the airfoil from moving radially-inward toward the disc, and

wherein the pair of clamp blocks that provide the root of the edge-mounted turbine blade are shaped to provide a second platform that extends circumferentially from the airfoil included in the edge-mounted turbine blade and is spaced radially outward from the radially-outermost surface of the disc to block hot gases interacting with a radially-outer portion of the airfoil from moving radially-inward toward the disc, and

wherein the slot-mounted turbine blade further includes retainers that each extend circumferentially from the root to overlap a portion of the root included in the edge-mounted turbine blade at a location radially inward of the platform and radially outward of the radially-outermost surface of the disc to block radially-outward movement of the edge-mounted turbine blade away from the disc.

2. The assembly of claim 1 , wherein the root of the edge-mounted turbine blade is bonded to the radially-outermost surface of the disc by a braze layer or a weld.

3. The assembly of claim 1 , wherein the platform of the slot-mounted turbine blade extends axially-forward and axially-aft of the airfoil included in the slot-mounted turbine blade, and wherein the platform of the edge-mounted turbine blade extends axially-forward and axially-aft of the airfoil included in the edge-mounted turbine blade.

4. The assembly of claim 1 , wherein the pair of clamp blocks included in the slot-mounted turbine blade are each shaped to include a recess that receives the radially inner portion of the airfoil included in the slot-mounted turbine blade, and the pair of clamp blocks included in the slot-mounted turbine blade are bonded to one another.

5. The assembly of claim 4 , wherein the pair of clamp blocks included in the edge-mounted turbine blade are each shaped to include a recess that receives the radially inner portion of the airfoil included in the edge-mounted turbine blade, and the pair of clamp blocks included in the edge-mounted turbine blade are bonded to one another.

6. The assembly of claim 1 , wherein the slot-mounted turbine blade has a radial height that is greater than a radial height of the edge-mounted turbine blade.

7. The assembly of claim 1 , wherein the edge-mounted turbine blade is arranged circumferentially adjacent to the slot-mounted turbine blade to provide a gap therebetween.

8. The assembly of claim 7 , wherein each retainer extends circumferentially from the root into the gap between the slot-mounted turbine blade and the edge-mounted turbine blade to overlap the root of the edge-mounted turbine blade.

9. A turbine wheel assembly, the assembly comprising

a disc made of metallic materials arranged around a central axis, the disc shaped to define a plurality of slots spaced around a circumference of the disc that each extend radially-inward from a radially-outermost surface of the disc,

a slot-mounted turbine blade including an airfoil made of ceramic matrix composite materials and a root that engages a radially-inner portion of the airfoil, the root being received in one of the plurality of slots defined by the disc and shaped to block radially-outward movement to decouple the slot-mounted turbine blade from the disc, and

an edge-mounted turbine blade including an airfoil made of ceramic matrix materials and a root, the root being bonded to the disc to couple the edge-mounted turbine blade to the disc,

wherein the root of the slot-mounted turbine blade is shaped to provide a platform that extends circumferentially from the airfoil included in the slot-mounted turbine blade and provides a portion of a gas path surface of a primary gas path that is spaced apart radially from the radially-outermost surface of the disc by a first distance to block hot gases within the gas path from moving radially-inward toward the disc, and

wherein the root of the edge-mounted turbine blade is shaped to provide a platform that extends circumferentially from the airfoil included in the edge-mounted turbine blade and provides a portion of the gas path surface of the primary gas path that is spaced apart radially from the radially-outermost surface of the disc by the first distance to block hot gases within the gas path from moving radially-inward toward the disc.

10. The assembly of claim 9 , wherein the edge-mounted turbine blade is arranged circumferentially adjacent to the slot-mounted turbine blade and is bonded to the radially-outermost surface of the disc.

11. The assembly of claim 10 , wherein the edge-mounted turbine blade is bonded to the radially-outermost surface of the disc by one of a braze layer and a weld.

12. The assembly of claim 9 , wherein the root of the edge-mounted turbine blade is made of metallic materials.

13. The assembly of claim 12 , wherein the root of the edge-mounted turbine blade is provided by a pair of clamp blocks shaped to receive a radially-inner portion of the airfoil included in the edge-mounted turbine blade and bonded to one another to prevent movement of one clamp block away from the other.

14. The assembly of claim 12 , wherein the root of the edge-mounted turbine blade is provided by a wrap shaped to receive a radially-inner portion of the airfoil included in the edge-mounted turbine blade.

15. The assembly of claim 9 , wherein the root of the slot-mounted turbine blade is made of metallic materials.

16. The assembly of claim 15 , wherein the root of the slot-mounted turbine blade is provided by a pair of clamp blocks shaped to receive a radially-inner portion of the airfoil included in the slot-mounted turbine blade and bonded to one another to prevent movement of one clamp block away from the other.

17. The assembly of claim 15 , wherein the root of the slot-mounted turbine blade is provided by a wrap shaped to receive a radially-inner portion of the airfoil included in the slot-mounted turbine blade.

18. The assembly of claim 9 , wherein the slot-mounted turbine blade further includes retainers that each extend circumferentially from the root to overlap a portion of the root included in the edge-mounted turbine blade at a location that is spaced radially inward of the platform and radially outward of the radially-outermost surface of the disc to block radially-outward movement of the edge-mounted turbine blade away from the disc.

19. The assembly of claim 18 , wherein the edge-mounted turbine blade is arranged circumferentially adjacent to the slot-mounted turbine blade to provide a gap therebetween that extends radially from the radially-outwardly facing surface of the disc to the platform of the slot-mounted turbine blade and the platform of the edge mount turbine blade, and wherein each retainer extends circumferentially from the root into the gap between the slot-mounted turbine blade and the edge-mounted turbine blade to overlap the root of the edge-mounted turbine blade.

20. The assembly of claim 9 , wherein the root of the edge-mounted turbine blade has a radially-inwardly facing surface that is bonded to the radially-outermost surface of the disc, the root of the slot-mounted turbine blade has a radially-inwardly facing surface that faces the disc when in one of the plurality of slots, and the platform of the slot-mounted turbine blade is spaced apart radially from the radially-inwardly facing surface of the root included in the slot-mounted turbine blade a second distance that is greater than the first distance.