METHOD FOR MANUFACTURING CERAMIC RODS IN INVESTMENT CASTING USING SELF-HARDENING MIXTURES (OPTIONS) Russian patent published in 2021 - IPC B22C1/02 B22C9/12 

FIELD: foundry.

SUBSTANCE: method for manufacturing ceramic rods in investment casting using self-hardening mixtures includes preparing a self-hardening mixture in air, evacuating it, manufacturing raw rods and drying them. Raw rods are made by pressing into metal single or multiple molds. The mixture self-curing in air contains, wt.%: refractory filler - granular white electrocorundum - 0.01-21.0, hardener - alkaline earth metal oxide - 4.0-7.5 and a suspension of the face layer based on an acidic aqueous colloidal binder - rest. Drying of pressed raw rods is carried out by loading them into a cold oven, then heating to 100°C at a rate of ≤5°C/min, holding at 100°C until moisture is completely removed, but not less than 6 hours, and cooling with the oven to 20°C.

EFFECT: reduction of formation of defects of the "gas porosity" type in castings made of heat-resistant alloys with an equiaxial structure.

30 cl, 5 tbl, 3 ex