SpaceX already makes turbine blades. For Merlin.
High heat, high RPM, cracks that NASA would not accept on a crew flight. They spent years on that and changed the part.
The next job is bigger blades for gas turbines that feed data centers.
Those parts sit in a few foundries with years of backlog. Elon wants the casting inside SpaceX to cut that wait by as much as 18 months.
Rocket blades exist.
Power-plant blades do not, not yet.