Method for manufacturing turbine blades with cooling ducts involves making ceramic core with positioning pins embedded in free end to protrude into surrounding moulding shell for removal during mechanical finishing of hardened blades

摘要

The method involves making a ceramic core, injecting round it with wax and dipping it and sanding it to produce a ceramic moulding shell. Movement of the core in the shell is prevented by positioning pins (7) embedded in the free end side (6) of the core (1) so as to protrude beyond this end side to bed into the shell. The protruding end of the pin is removed during the mechanical finishing work carried out on the hardened metal blades. The pin is made from a nickel-based alloy, preferably from NiCr 82.