A composition of water-soluble ceramic core for investment casting and process of ceramic core by its composition

摘要

PURPOSE: A water soluble ceramic core composition for investment casting, a ceramic core prepared by using the composition and its preparation method are provided, which core is improved in the dimension stability and the dissolution in water and is useful to the investment casting process of a metal reactive to an acid or base. CONSTITUTION: The water soluble ceramic core composition comprises 60-75 wt% of a fused silica; 20-30 wt% of tribasic potassium phosphate; and 5-10 wt% of water. Preferably the fused silica has a particle size of 45 micrometers or less or 100-200 micrometers. The preparation method of a ceramic core comprises the steps of mixing a fused silica with tribasic potassium phosphate; extruding the mixture from a mold with an extrusion pressure of 20-200 kgf/cm2; stabilizing the extruded one; drying the stabilized one; and sintering the dried one at 800-950 deg.C.