METHOD OF MAKING CERAMIC MOULD FOR MELTING WAX PATTERNS Russian patent published in 2020 - IPC B22C1/02 B22C9/12 

FIELD: foundry.

SUBSTANCE: invention relates to foundry production and can be used in casting of turbine blades from heat-resistant alloys. On the model block a refractory coating is applied, each layer is sprinkled with granular electrocorundum, dried, the model is removed and calcined. Suspension of face layer has the following composition (wt. %): acidic water-colloidal binder (43.0–47.0), powder-sillimanite powder concentrate (53.0–57.0). Face layer is dried on conveyor. Refractory suspension of the following layers, up to the eighth one, has the following composition (wt. %): highly alkaline water-colloidal binder (27.0–29.0), micro powder of white electrocorundum of F360 fraction (49.0–51.0), microsweet powder of white electrocorundum fractions F1000 or F1200 (16.0–18.0), aluminium powder (4.0–6.0). These layers are dried on conveyor in climatic chamber. Final drying is performed in climatic chamber for at least 12 hours. During tempering, mould is loaded into furnace, heated to 300 °C, held for 5 hours, heated to 1070–1100 °C with speed ≤ 3 °C/min, held for 7 hours and cooled with a furnace at a rate of ≥ 5 °C/min up to 100–20 °C.

EFFECT: higher durability of suspension and automated production of ceramic moulds.

3 cl, 1 dwg, 3 ex, 2 tbl