The no machining directional solidification hollow turbine blades, hollow guide vans and complex structure parts used in aero engine and gas turbine made by vacuum precision investment casting.
Shenzhen Zen alluvial gold velvet with gold, silver and copper as raw material, the electric casting is hollow, some manufacturers use is resin embryoid body, process and value will vary.
If a hollowcasting is to be made the pattern will include extension pieces so that Spaces to accept the sand core are molded into the sand. These additional Spaces in the mold are termed core prints.