CORES OF DIFFUSABLE SILICONE NITRIDE CERAMIC CORES

摘要

A method of producing cast articles having internal cavities is disclosed. The method is particularly suitable for casting gas turbine components from nickel base and cobalt base superalloys. The method comprises: forming a core to the desired cavity configuration, the core consisting essentially of densified silicon nitride; securing the core within a mold; casting the alloy within the mold and around the core; removing the solidified cast article from the mold; and leaching the silicon nitride core from the casting in molten sodium hydroxide.