A turbine blade is a radial aerofoil mounted in the rim of a turbine disc and which produces a tangential force which rotates a turbine rotor.[2] Each turbine disc has many blades.[3] As such they are used in gas turbine engines and steam turbines. The blades are responsible for extracting energy from the high temperature, high pressure gas produced by the combustor. The turbine blades are often the limiting component of gas turbines.[4] 

Turbine blades are made through a complex manufacturing process, often involving investment casting or composite construction, depending on the type of turbine and materials used. Common materials include nickel-based superalloys for high-temperature applications and fiberglass/epoxy composites for wind turbine blades. The process includes creating molds, shaping the blade, potentially adding internal structures, and applying surface treatments for durability. 

Here's a more detailed look at the manufacturing process:

1. Material Selection:

Gas Turbine Blades:

Nickel-based superalloys are often chosen for their ability to withstand high temperatures and stresses. 

2. Mold Creation:

Investment Casting: Wax patterns are created in the shape of the desired blade. These are then invested in a ceramic shell mold. 

Composite Layup: For composite blades, molds are created based on the blade design. 

3. Shaping the Blade:

Casting:

Molten metal is poured into the ceramic mold, and allowed to cool and solidify. 

4. Internal Structures and Features:

Ribs and Spars:

Internal structures like ribs and spars are often incorporated into composite blades to increase stiffness and strength. 

Cooling Channels:

Gas turbine blades may incorporate cooling channels for thermal management. 

5. Surface Finishing: 

Investment Casting:

Blades may be subjected to heat treatment and machining to achieve the desired surface finish and dimensional accuracy.

Composite Blades:

Surface finishing, including sanding and polishing, is performed to refine the blade's aerodynamic profile.

6. Quality Control:

Non-Destructive Testing:

Blades are inspected using techniques like X-ray and ultrasonic testing to identify any internal flaws. 

Dimensional Checks

Blade dimensions are carefully verified to ensure they meet design specifications. 

7. Final Assembly: 

Gas Turbines: Blades are attached to the turbine rotor.

In summary, the manufacturing of turbine blades is a sophisticated process that requires precise engineering, advanced materials, and rigorous quality control to ensure optimal performance and longevity.