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 dissolved sodium chloride with fraction size 0.1 -0.63 mm; using mixture with next relation of ingredients (vol.%): investment components, 75 - 80; sodium chloride, 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 expansion of pattern at heating it during melting it out of ceramic envelope. EFFECT: enhanced accuracy of dimensions and geometry of castings and patterns. 1 tbl