METHOD OF PRODUCING OF COMBINED SHELL MOULDS AS PER CONSUMABLE PATTERNS TO PRODUCE CASTINGS OUT OF HEAT-RESISTANT ALLOYS WITH DIRECTED AND SINGLE-CRYSTAL STRUCTURES

摘要

FIELD: metallurgy.;SUBSTANCE: model is made. Layer after layer the heat-resistant suspension based on dusty electrocorundum is applied to the model. The first two layers are applied with use in the heat-resistant suspension of the organoaluminium binding, containing chelated polyalkoxyalumoxan 20-30 wt % and aliphatic alcohol - rest up to 100%. Further layers are applied using the suspension based on binding of hydrolysed ethyl silicate with addition of catalyst of agglomeration of aluminium powder "АСД-4". Further dusting of each layer by grainy electrocorundum is performed. The first two layers are dried at 100% humidity ensured by water spraying or spattering, with further convection drying by air blowing for 2-3 hours under workshop conditions at 23-25°C. Model is removed. Moulds are baked at 1200-1350°C for 8-12 hours.;EFFECT: increased strength of the mould material, reduced chemical interaction at border metal-mould, and reduced roughness of castings.;1 tbl, 2 ex