A schematic illustration of the vacuum-casting process, or countergraz/ity lowpressure
(CL) process (not to be confused with the vacuum-molding process described
in Section 11.2.1) is shown in Fig. 11.18. Vacuum casting is an alternative to investment,
shell~mold, and green-sand casting and is suitable particularly for thin-walled
(0.75 mm) complex shapes with uniform properties. Typical parts made are superalloy
gas-turbine components with walls as thin as 0.5 mm.