The investment casting shell making process using silica sol as a binder has been widely used, but when producing pipes and valve products with curved cavity structures, the inner cavity sand is difficult to remove. By utilizing the characteristics of coated sand and combining the characteristics of silica sol shell making, the sand inside the curved cavity structure casting can be removed more easily.
In the silica sol investment casting process of curved cavity structure products, the strength of the inner and outer shell layers can be improved by changing the refractory material used for sand hanging and formulating the corresponding process. The application of coated sand with appropriate performance requirements can improve the collapsibility of the shell layer in the silica sol investment casting process, providing a solution to the sand cleaning problem of precision castings with complex cavities.