METHOD FOR MAKING INVESTMENT PATTERNS Russian patent published in 2003 - IPC

FIELD: casting with use of investment patterns in machine engineering. SUBSTANCE: method comprises steps of making pattern of powdered mixture containing investment pattern material with fraction size 0.1 - 1.6 mm and sodium carbonate with fraction size 0.01-0.3 mm; using mixture with next relation of ingredients (vol. %): investment components, 75 -80; sodium carbonate, 20 -25; metering pattern material to press-mold in quantity providing manufacture of patterns with porosity degree 3 -10%; without preliminary heating pressing pattern material at joining parting surfaces of press mold; sintering pattern material at pressing practically without phase deformation at forming open capillary porosity for compensating pattern expansion at heating it during melting it out of ceramic envelope. EFFECT: enhanced accuracy of dimensions and geometry of patterns and castings. 1 tbl